This is a pre-configured version of the game that does not require Origin or a disc drive. It is heavily compressed to make downloading faster.
Is this piracy? Technically, yes. The Sims 2 Ultimate Collection is not freeware. It is abandonware – EA no longer sells it, but they still hold the copyright. However, EA officially gave away the Ultimate Collection for free in 2014 to anyone who redeemed a promo code. Many players argue that rehosting that same build is ethically acceptable because: The Sims 2 Ultimate Collection 2014 Multi 21 Repack Mr DJ
If you want to stay 100% legal: find an old Origin account that redeemed the 2014 UC giveaway, download the official version, then add the Mr DJ patches manually. But for 99% of users, this repack is the only practical way to play. This is a pre-configured version of the game