Web application – a program with a two-tier “client-server” architecture. The client interacts with the user interface (UI/UX) through web-browser pages. All data is stored on the server, the exchange takes place through the network protocols HTTP/HTTPS.

Web Application works as a cross-platform program regardless of the operating system in the mobile version (Android or iOS) and desktop version (Mac OS, Windows, Linux). Running the program does not load the device, and you only need a browser on the Internet to work.

When creating web applications, programmers create a complex architecture with which the user interacts after authentication. Programming techniques such as JavaScript, HTML5, CSS and frameworks are used or the code is written by hand.

Languages and frameworks of the main parts in Web App:

Backend (server-side).
The “under-the-hood” part that is not visible to the client – the system, databases, architecture, logic – is set up. Programmers develop web applications in Python, Java, PHP, Go, C#, Ruby, Node.JS, and use server technologies (Apache, Nginx, AJAX).

Frontend (client side).
The frontend developer implements the part of the program visible in the browser, with which the client interacts to enter data or receive feedback. The most often used programming language is HTML – marking up the hypertext, CSS – working with styles, JavaScript – creating an interactive page, as well as related frameworks.

DevOps programming (automation).
The DevOps team or hosting provider configures the program’s hosting infrastructure.