Usually removes pre-installed apps, Metro UI (Start Screen), Cortana, Windows Defender, Windows Update, printer drivers, and sometimes network components to save RAM and disk space.
These "Lite" editions are rarely created by Microsoft. They are often modified by third parties who may remove crucial security components (like Windows Defender, UAC, or Windows Update) or, worse, bundle the installation with malware, rootkits, or spyware. Windows 8.1 Lite Edition 2017 Free Download
You cannot receive official updates, making the system vulnerable to new security threats. Usually removes pre-installed apps, Metro UI (Start Screen),
If you have a completely separate, obsolete computer you want to test with for fun, it may work, but it is not recommended. Safer Alternatives You cannot receive official updates, making the system
Here is a solid, critical review of such products based on community consensus, security principles, and performance testing of modified Windows ISOs: ⚠️ Critical Risks and Warnings
If you are looking to speed up an old computer, let me know: does it have? Is it using a traditional HDD or an SSD ?
While the goal is to make it "fast," removing too many components often results in an unstable system that crashes or breaks key functionality (like networking or USB driver support).