Single turn encoder
This type of encoder does not store information on the "number of turns". For each position of the shaft, it delivers a single data item in the form of a "word" in parallel or serial mode, which can be read directly and quickly by control systems.
Multiturn encoder
This type of encoder can perform a greater number of turns and delivers, in addition to the position of the shaft in the turn, the number of turns performed in relation to a reference point.