Windows 7: No issue if I choose to delete my old backups??

Look like my backup is getting huge as it run on daily schedule.

There's no issue if I choose to delete my old backup and retain the latest, right?
For instance, I start backing up on Nov till Jan. I deleted Nov, Dec and Jan Backup, retaining the latest one only. Start re run the backup, the system will detect and re backup the modified files/ folders?

If this is correct, will my files be as huge as now?

I just worry that if I deleted the dates that I backup before, it will not be backup at all.

Hope that I didn't sound confusing tho.

If you are talking about system restore, no problem

I find that a restore point several times a week, plus a system image is the best way for me. If a problem does arise, I have old points to return to. I may have a virus even today and not realize for many weeks.

Take care.

No problem, just depends on what type of backup is being done.
When I USED TO have Windows 7 do a file backup AND an image backup, I would once in a while goto manage backups, delete them all, and Windows would prompt me to create a new backup, which I clicked yes to.
Now I only use the image backup, as I am backing up an entire SSD to another drive in the laptop. Drive space remains about the same. Once a week I copy the data drive to an external drive using terracopy set on overwrite older only.
System image backups are finished in 4-5 minutes once a day because I am paranoid (and don't use System restore).

Image back up mean the entire C drive or the entire drive plus folder. I have 3 x HDDs to back up tho.....