Composer is a dependency manager for PHP. You can describe what additional libraries are necessary for the work of your project and Composer will install them for you.

Briefly about how Composer works. For example, your project depends on several libraries, in turn, these libraries depend on other libraries (and so on). You describe those libraries on which your code depends, and Composer finds the necessary libraries for the work of your project, downloads and installs them. Everything, your project is ready to work.

And so we proceed to installation.

Install Composer on Windows is very simple. First you need to download the installation file from the official site https://getcomposer.org/download/. Link to the installer itself: https://getcomposer.org/Composer-Setup.exe. Download it and run it and click "Next":

Then check "Install Shell Menus", so that the composer can be launched from the context menu (the pop-up menu by clicking on the right mouse button). And click "Next":

In the next window, you need to specify the path to php.exe and click "Next":

Next, click "Install" and "Finish":

Everything, composer is installed. Let's check, open the Windows console (Win + r and enter cmd) and enter the command:

composer

You should see the following:

Also check the context menu, open "My Computer", find any file and right click on it. You should see something like: