real time

Short definition from Wiktionary

Noun

1. 1
   The duration required by a computer system to complete a particular task.
2. 2
   The time during which an event or process occurs (and during which, without much delay, it is responded to, reacted to, etc).
3. 3
   Used other than figuratively or idiomatically: see real, time.

Adjective

1. 1
   Communicated as the events being responded to occur; communicated or proceeding without much delay.
2. 2
   Of a system: that responds to events or signals within a predictable time after their occurrence; specifically the response time must be within the maximum allowed, but is typically synchronous.