GarageBand Instruments are actually less CPU and memory-intensive versions of equivalent Logic Pro instrument plug-ins. The GarageBand synthesizers use a cut-down version of the ES2. Similarly, organ sounds are generated by a feature-limited EVB3, and electric piano sounds are emulated by an instrument based on the EVP88. Other sounds, such as strings, brass, drum kits, and so on, make use of a simplified sample player that is based on the EXS24 mkII.
The interface of all GarageBand instruments is limited to a few key parameters, simplifying their use. The available parameters were carefully chosen to provide maximum impact and flexibility, making it easy and fast to create great sounds.
The inclusion of these instruments makes it simple to import GarageBand project files into Logic Pro. After you import a GarageBand project, you will have access to the advanced sequencing, mixing, and effect processing options in Logic Pro. You can also choose to replace the instruments in your GarageBand project with any of the Logic Pro instruments.