# What is the purpose of Vih and Vil in the comparator's datasheet?

Looking into the MAX999 datasheet I can not figure out how to utilize information given for the Vih and Vil

Logic-Input High --- Vih --- (Vcc/2 + 0.4) min
Logic-Input Low  --- Vil --- (Vcc/2 - 0.4) max


The rest of datasheet says nothing about inputs' ability to be configured as logic inputs - it is the output which is logic level. What is the purpose of this information then?