counts as units in encoder file?

I’m wondering what are counts in the following code which is in the smart motors and encoders sample file in Vex IQ? task main()
{
//Reset the current position in the motor encoder to zero.
resetMotorEncoder(leftMotor);
resetMotorEncoder(rightMotor);
//Set motor to run 5000 counts at power level 75.
moveMotorTarget(leftMotor, 5000, 75);
moveMotorTarget(rightMotor, 5000, 75);
//Blocking command prevents program from continuing until movement is complete.
waitUntilMotorStop(leftMotor);
waitUntilMotorStop(rightMotor);

Last year, we worked with rotations and degrees. We never came across counts.

Many thanks in anticipation.
Máire.