EQ which is a common abbreviation from Equaliser refers to a hardware unit or software that is able to adjust the level of incoming audio by frequency.
EQ next to compression is the most commonly use effect within audio production whether it be in a live environment or in the studio environment.
There are a few different types of EQ units available that have different characters or indeed different purposes altogether. Logic does support a variety of different EQ modules.
Channel EQ , named to be the most commonly used EQ in Logic Pro. This is a parametric multi-band EQ. This means it supports more than one filter across the frequency spectrum. The parametric element simply means the filters can be moved both up and down the frequency spectrum as well as provide cut and boost with varying Q controls. Channel EQ’s are designed to serve the most commonly required mixing purposes while remaining uncharacteristic and transparent. (Note there is a Linear Phase version of this EQ also)
Match EQ, is a specialist tool for collecting data on the frequency content of one sound source and then applying that profile to another sound.