If you are looking for the specific features included in the 2021 release (v25.x), the official version introduced several enhancements:
: 4 GB of available hard-disk space for installation. Safe and Legal Alternatives
: Multicore Intel processor (64-bit) or ARM-based Apple Silicon.
Using software from unofficial sources like Rahim Soft comes with serious drawbacks:
: Version 2021 was the first to support ARM-based Apple Silicon (M1 chips) via Rosetta 2 emulation. Risks of Using Unofficial Portable Software