Sync folders and volumes, or create a bootable clone of your Mac startup disk.
If you’re confused about which backup utility to use, it’s understandable — there are many to choose from, and each is good in its own way. Recently, though, SuperDuper has risen head and shoulders above the others as the best of the best. The freeware version allows you backup and clone your drive. For extra features, you have to pay.
Customize backup intervals for Time Machine — by number of hours, by calendar date and time, or when inactive. Macworld has a good writeup.