Learning JUNOS from IOS - Day2 (Configuration Management)

Configuration Management Day 2 - How to review router configuration ? In Cisco IOS, it has two default configuration files: (1) startup-config: is used for initialization of router boot up process (2) running-config. is the real-time concurrent configuration repository whenever you type any commands in IOS. And how do you differentiate screen output is the startup-config or running-config ?