The version you're looking at, Windows 8.1 Pro VL x86 Multi-6 ESD Preactivated, is an unofficial, highly modified installer typically found on third-party sites like Scribd. While it may promise a "free" and "fully activated" experience, using it carries significant security risks. What the Name Means
Conclusion
ESD (Electronic Software Download): A compressed file format used to reduce the size of the installation media. full windows 81 pro vl x86 multi6 esd preactivated free
x86: This denotes that the operating system is compatible with 32-bit processors. The version you're looking at, Windows 8