When you want to save your configurations, you will be typing the following:
After typing the copy run start command, just hit the Enter key twice and your configurations will be saved to NVRAM.
If you want to erase the entire startup-config file, which is in NVRAM, you would need to perform the following steps:
As shown in the preceding screenshot, you would have to type out erase start, which is short for startup-configuration; hit the Enter key to confirm this decision and then reload the router. You have just erased all your configurations on your router.
To view your existing configurations type show run; to view what is already saved type show start.