They often remove unnecessary components like extra languages or background telemetry services to speed up the installation.
Some repacks are "portable," meaning they can run from a USB drive without a full system installation. Technical Requirements for 64-bit Performance adobe photoshop cc 2015 20150529r88 64bit repack
Allowed users to make a change to an asset once and have it update across all Photoshop, Illustrator, or InDesign projects. A streamlined mode for web and app designers
A streamlined mode for web and app designers that stripped away unnecessary tools to focus on layout. Key Features of the 2015 Release
Released as part of the Creative Cloud suite, the 2015 version introduced several groundbreaking features that changed the digital imaging landscape. It moved away from the "one-time purchase" model of the CS (Creative Suite) era, focusing instead on cloud integration and continuous updates. Key Features of the 2015 Release