How do you navigate between the different IOS modes? List the commands to move up and down the hierarchy.

Go up with enable then configure terminal, then into sub-modes with line/interface; come back with exit (one level) or end/Ctrl+Z (straight to Privileged EXEC).

IOS arranges its commands in a hierarchy of modes, and you can only run a given command from the mode it belongs to — so navigating that hierarchy is a constant part of configuring a device. You move deeper (more privilege, more specific scope) one step at a time, and you can climb back out either one level or all the way to the top.

* Going deeper (cyan) vs. climbing out: exit steps back one level (red), end or Ctrl+Z jumps straight to Privileged EXEC (yellow). *

Moving deeper:

• enable — User EXEC → Privileged EXEC; unlocks the full command set (show, configure, etc.)
• configure terminal — Privileged EXEC → Global Config; from here on you are changing the device's configuration
• line console 0 / line vty 0 15 — Global Config → Line Config; selects the console or the remote (VTY) lines so you can secure them
• interface FastEthernet 0/1 — Global Config → Interface Config; selects one port to configure

Climbing back out:

• exit — steps back exactly one level
• end or Ctrl+Z — jumps straight back to Privileged EXEC from any config mode, no matter how deep you are

The prompt always tells you where you are (e.g. (config-if)# means interface config), so read it before typing a command.

Go deeper:

• Jeremy's IT Lab — Intro to the CLI (CCNA Day 4) — demonstrates enable / configure terminal / exit / end navigation hands-on.
• Cisco IOS — command modes (Wikipedia) — the mode hierarchy these commands move through.