What does standby and usage mean on iPhone?

People say that when they describe their batteries…

Standby = phone is on standby when the battery isn't bring used
Usage= amount of battery being used

Standby is when you have your phone
Locked and in your pocket or whatever. Usage is when you have your phone phone out an are texting or whatever your doing.

Standby means that your phone is on but not in use. Like it is locked in your pocket or the display is off. Standby in batteries is how long the phone gets on standby time. So basically from a battery stand point, standby is your battery life of your phone while it is not in use. Usage means when it is being used. The usage battery life is counting anything from when the display is on.