What is Session ?
Session is (noun) 1. the time when an activity is taking place All these long sessions in front of the computer screen are ruining my eyesight. a practice session a time when someone, e.g. an athlete or a ten- nis player, practises 2. a meeting, e.g. of a committee or of parliament The first ses- sion of the all-party talks will be held on Monday. opening or closing session the first or last part of a conference in session in the process of meeting The committee has been in session for two hours.
source: Easier English, Student Dictionary Upper Intermediate Level