Backup software confusing

Firstly, a flash drive would not be my first choice as a backup. No matter how reputable, how pricey, how big (storage wise), flash drives are notoriously unreliable as a permanent/long term storage option.

Options
An external USB drive
Cloud storage

No point in having a backup to your PC .. what if it goes pear-shaped or gets nicked - both original/source data AND backup are gone.

Backup? What are you trying to backup?

Option
Imaging (one file containing all data) - good for systems backup
Personal data (documents, pictures, music videos, et al - backup in native format doc as doc, jpg as jpg, file by file) or imaging (one file all data)

Compromised system
- restore an image (same siftware as used to create it - Macrium Reflect, AOMEI Backupper, etc)
- copy and paste native format files

Me, I use multiple scheduled backup systems
- Macrium Reflect, image, full backup 2 days x week
- AOEMEI, image, full backup 2 other days a week
(both the above done overnight, scheduled, unattended. I don't worry about incremental/etc, just full backups)
- SyncBackfree, nightly, all personal data files

EDIT If it's just your personal data, why not get a Gmail account, install Google Drive and (auto) backup to your Gmail account cloud

(Note If you're that unfamiliar with backup methods/options/etc, I'm not even going to go near Microsoft OneDrive, which needs to be understood and rigidly controlled from the first click otherwise ... it will only end in tears)

AOMEI Backupper is very easy to use.

@ander35 Our good friend @Ghot made guides with screenshots for 2 of the most commonly used backup programs , Macrium and Aoemi Backupper. This is for a full system image.

Let's see if I can simplify for you.
What you need to create a full system backup image:
A backup program of your choice which you install on your computer.

A small (4-8gb )flash drive.....This is to create a bootable recovery drive that has a copy of whatever backup program you choose to use to image your system.Once you install the program, you tell it to create it's recovery media. In case of emergency, you boot your computer from this flash drive, instruct the program to restore. You tell the program where your backup image is located, and what disk you want to restore the image to. The program does the rest.

Some place to store your image....This is where the backup program will store the "copy"(ie image) of your system. It has to be large enough to store your images. You CAN use a large flash drive if that's all you have, but most people do use an external hard drive as its size can accommodate more than one image and the images can be written more quickly.
Another lesser used option is some cloud storage provider.

Other ways to backup your data
Know that full imaging using backup software is not the only way to protect yourself against losing your data. One can make his backup scheme as elaborate as he chooses. A lot of people do not use any backup program at all.
Many sync all their personal data on their system to a cloud storage provider, most commonly Onedrive or Google Drive.
Many do the simplest backup of all...they copy all their personal folders to some external media. In this case a flash drive would work fine. If your system ever fails, the operating system can always be re-installed and your data files can be copied from your flash drive.

How often one chooses to backup is subjective and different for everyone and their needs. The same goes for HOW one backs up. The important thing is to take SOME steps, however simple or elaborate, to protect the data that is important to you.