Players often download "New Species" or "Total Overhaul" mods from sites like Nexus Mods that come in compressed formats.
To open a .rar file, you need an extraction tool like WinRAR or 7-Zip. Jurassic-World-Evolution-2.rar
Large files (often split into parts around 4.95 GB) can be "repacks" used for easier downloading of the full game and its DLCs. How To Mod Jurassic World Evolution 2 - An Easy Guide Players often download "New Species" or "Total Overhaul"