Thumbnail - a small-sized, concise, and compact representation of images or videos. Such reduced copies are a common practice in any programs and web applications for working with graphic files (raster, vector, fractal) and video-records.
In this case, thumbnails can be widely used for any information that the user is accustomed to perceive visually (CAD drawings, 3D models, a screenshot of the current place in the save in the game, etc.).
When working with video, thumbnails are also often used. In the video editor on the timeline, a user can display reduced copies of keyframes to navigate faster. If this is a software application for watching videos, then for the presentation you can automatically or manually select a thumbnail for an image. Some programs and Web services generate several thumbnails for one video at a time. When viewing a set of videos, they display only one of them, but when you hover the mouse cursor over a thumbnail, it is quickly replaced by others so that the user gets a better idea of the video that interests him.
Thumbnails usually have only a descriptive function. Therefore, in order to save resources, without significantly poor resolution and damage, they can be saved in less quality than the original one.
Thumbnails also do not have to be stored in the same format as the original image. The developer can choose some uniform format for everyone to simplify the task. Based on the same descriptive function, for a thumbnail you can not use the whole image, but only its fragment. Often this can be even more informative and useful. Some images turn into an uninformative pixel mush (for example, schemes), and then it is clearly better to use the recognizable fragment.
Each manufacturer of a software product usually determines the fixed maximum sizes of thumbnails (usually the same for width and height). To create them, the images are proportionally reduced so that the larger size does not exceed the specified limit. This simplifies the design of the user interface, as the developer is confident that the picture does not go beyond a certain size.
is computer software in the early testing phase. It has basic functions enough to be used, but it is often buggy and lacks features that will be integrated into the final version. Alpha software is often used for internal testing.
Internal (Alpha) testing - The stage of testing the program as a whole by testers, usually not developers of the software product, but, as a rule, within the organization or the community developing the product. Also, it can be the stage of adding new functionality, whereby programs can only be used to familiarize themselves with future opportunities.
Most often, alpha testing is carried out at an early stage of software development, but in some cases, it can be used for a finished product as an internal acceptance test. Sometimes alpha testing is performed under a debugger or using an integrated development environment that helps to quickly identify the errors found. The detected bugs can be reported to testers for additional investigation in an environment similar to the one in which the program will be used.
Typically, alpha testing ends with freezing properties and goes into beta testing.
Beta testing - The stage of active public testing and debugging of the program that passed the alpha testing (if any). Programs of this level can be used by other developers of software for compatibility testing. Nevertheless, the programs of this stage can still contain a large number of errors.
Sometimes beta testing is performed in order to get feedback about the product from its future users.
Often for free and open source software, the alpha testing phase is characterized by the functional content of the code, and beta testing is the error correction stage. At the same time, as a rule, at each stage of development, intermediate results of work are available to end users.
Cloud computing often referred as the cloud, the practice of using a network of remote servers to store, manage, and process data, rather than a local server or computer.
Via cloud model the user can easily get a convenient web access to computing resources (for example, servers, storage devices, data networks, applications and services - both together and separately) that can be promptly provided and released with minimal operating costs, paid to the cloud computing provider.
The National Institute of Standards and Technology (NIST) recorded the following mandatory characteristics of cloud computing:
Self-service on demand - the consumer independently identifies and changes computing needs, such as server time, access and processing speeds, the amount of stored data without interacting with a representative of the service provider;
Universal access over the network - services are available to consumers over the data network, regardless of the device used;
Resource pooling - a service provider integrates resources to serve a large number of consumers in a single pool for dynamic redistribution of capacity between consumers in a constantly changing demand; while consumers control only the basic parameters of the service (for example, data volume, access speed), but the actual distribution of resources provided to the consumer is performed by the supplier ;
Elasticity - services can be provided, expanded, narrowed at any time, without additional costs for interaction with the supplier, usually in automatic mode;
Consumption accounting - the service provider automatically calculates the consumed resources at a certain level of abstraction (for example, the amount of data stored, the bandwidth, the number of users, the number of transactions) and, based on this data, estimates the volume of services provided to consumers.
Private cloud is an infrastructure intended for use by one organization, including several consumers (for example, units of the same organization), possibly also customers and contractors of this organization. A private cloud can be owned, managed and operated by both the organization itself and a third party (or some combination thereof), and it can physically exist both inside and outside the owner's jurisdiction.
The public cloud is an infrastructure designed for free use by the general public. A public cloud can be owned, managed and operated by commercial, scientific and government organizations (or some combination thereof). A public cloud exists physically in the jurisdiction of the owner-provider of services.
The community cloud is a kind of infrastructure intended for use by a specific community of consumers from organizations that have common tasks (for example, security requirements, policies, missions, and compliance with different requirements). A public cloud may be co-operative (co-owned), managed and operated by one or more community organizations or a third party (or any combination thereof), and it can physically exist both inside and outside the owner's jurisdiction.
A hybrid cloud is a combination of two or more different cloud infrastructures (private, public or community) that remain unique objects but are linked together by standardized or proprietary data and application technologies (for example, short-term use of public cloud resources for load balancing between clouds).
Commercial software is software designed to make profit by other means; for example, by selling copies.
Many people mistake commercial and free software; they often get it the wrong way round. Above all, software is considered free from the moment the author grants the rights to modify, distribute and extract profits from the product. Free software may be commercial products as well. Good examples of commercial programs that are classified as free are the GNU ADA compiler or many GNU/Linux based operating systems.
The opposite of free software is proprietary software, which can also be commercial or freeware.
Freeware is the software licensing agreement that does not require any payments to the right holder. Freeware is usually distributed in binary form, without source codes and is regarded as proprietary software. Freeware, unlike shareware, does not involve any fee to the developer. No additional services, such as improved versions, are expected.
Shareware is software with royalty-free (or reimbursable under certain conditions) use.
Proprietary software is software that is the private property of authors or rights holders and does not satisfy the criteria of free software (the availability of open source code is not enough). The owner of proprietary software retains the monopoly on its use, copying and modification, in full or essential moments. Typically, any non-free software, including semi-free software, is called proprietary.
Command line interface (CLI) - a kind of textual interface between a person and a computer, in which computer instructions are given mainly by typing text strings (commands) from the keyboard, on UNIX-systems it is possible to use a mouse. Also known as the console user interface.
The command-line interface, often mentioned as command-line user interface, is contrasted with the menu-based control systems of the program, as well as to various implementations of the graphic user interface (GUI).
The output format of the information in the command-line interface is not regulated; usually, this is a simple text output, but it can also be graphic, audio, etc.
If the program is fully or almost completely managed by commands from the command line interface, and supports a batch interface, a skilful combination of the command line interface with a graphical interface provides the user with very powerful capabilities.
Historically, the main areas of application of the command line interface were on computer terminals in 1960-1980s, for MS-DOS, Unix operational systems and later on on Apple DOS. Now it’s used for chats, computer games and program testing.
is an application store accessed via iTunes containing various apps for iPhone smartphones, iPod Touch, iPad tablets, and also for Mac personal computers and allowing to buy them or download for free. Similar to Google Play for Android applications.
Costs for an App range from $ 0.99 to $ 9.99, and significantly more for professional software. However, most apps are distributed through the App Store for free.
The store is supervised by Apple experts. Each application is equipped with a special electronic certificate. If somebody starts to commit illegal actions with the purchased program, they will remove it from the database, and developers will be "severely reprimanded".
Revenues from sales of apps are distributed as follows - the authors receive 70%, Apple collects 30% of the share in order to maintain the store. Officially, Apple claims that they don’t intend to make money on sales. Developers also have an opportunity to release free apps. It is also interesting that all purchased programs can be registered in iTunes to download all the new updates.
In the iPod Touch, the App Store service works when you connect to the Internet via Wi-Fi. So users can buy and download apps through the wireless network from anywhere. Applications are available either for free or have a certain cost which is charged from the user's account in the iTunes Store.
The App Store will promptly notify the user about the latest updates, which happens regularly. The App Store service is available in iTunes for both Macs and personal computers, wherein apps are synchronized with the iPhone or iPod Touch via a USB interface.
Content management system (CMS) - information system or a computer program with simple and convenient user interface, used to provide and organize a joint process of creating, editing and managing content without special programming knowledge.
The content management system can contain a wide variety of data: documents, films, photographs, phone numbers, scientific data, and so on. Such a system is often used to store, manage, review and publish documentation.
Version control is one of its main advantages when the content is changed by a group of people.
In general, content management systems are divided into:
The term CMS replaced WCMS, becoming a synonym for the website management system.
Such CMS allows you to manage the text and graphic content of a website, providing the user with an interface for working with the content of the site, convenient tools for storing and publishing information, and automating the processes of placing information in databases and issuing it to HTML.
There are many ready-made content management systems, including free ones. They can be divided into three types according to the mode of operation:
Most of the modern CMS are implemented as a visual (WYSIWYG) editor - a program that creates HTML code from a special simplified markup that allows the user to easily format the text.