Response time: Response time can be explained as the amount of time it takes the system or server to respond to individual client request, this is an important criteria used when evaluating the system performance.
Load: The load being referred to here is the amount or the total number of users, usually depicted as (N) that are using the application simultaneously or sending requests to the server at the same time.
Stability: This is could be said or describe as a factor used to gauge the system's behavior when there is load on it.