This page doesn't actually tell you anything about how to install PHP. And the pages about IIS and Apache say you have to do this first!
PHP is only available for 32-bit x86 or 64-bit x64 systems, and does not currently run on Windows RT or Windows on ARM. As of version 8.3.0, PHP requires Windows 8 or Windows Server 2012. Versions after 7.2.0 required Windows 2008 R2 or Windows 7. Versions before 7.2.0 supported Windows 2008 and Vista.
PHP requires the Visual C runtime (CRT). Many other applications also require it, so it is likely to already be installed, but if it is not the Microsoft Visual C++ Redistributable for Visual Studio 2022 is suitable for use with all PHP versions and can be » downloaded from Microsoft.
The x86 CRT must be downloaded for use with PHP x86 builds and the x64 CRT for PHP x64 builds. If CRT is already installed, the installer will display a message that it was already installed and not make any changes. The CRT installer supports the /quiet and /norestart command-line switches, so the installation can be scripted.
Windows builds can be downloaded from » the PHP Windows website. All builds are optimized (PGO), and QA and GA releases are thoroughly tested.
PECL extensions that are pre-built for Windows are available from » the PECL downloads section of the PHP Windows website.
Binaries are not available for extensions that use features specific to other systems, like Unix, or depend on libraries that are not available on Windows.
There are four types of PHP builds:
Thread-Safe (TS) - for single process web servers, like Apache with mod_php
Non-Thread-Safe (NTS) - for IIS and other FastCGI web servers (Apache with mod_fastcgi) and recommended for command-line scripts
x86 - for 32-bit systems.
x64 - for 64-bit systems.
This page doesn't actually tell you anything about how to install PHP. And the pages about IIS and Apache say you have to do this first!