They may include additional tags for engine evaluations, move times, or specific opening classifications that standard PGN readers might not always display by default.

These files often contain massive libraries of Grandmaster games or engine-vs-engine matches (like those from TCEC or CCC).

The gold standard for weekly Grandmaster game updates.

Use a virtual machine or a "sandbox" environment to extract the files if the source is unverified.

If you are looking for high-quality, safe game data, these established repositories are generally preferred over random rar downloads:

Because PGN is a text-based format, it can become incredibly bulky. A .rar archive is used to shrink these multi-gigabyte text files into a manageable download size. Risk and Verification