Help About HD Tune Results

Good day everyone, can anybody help me to interpret the results after the HD tune of my HDD.
I am not an IT Professional so I do not know the results.

Reallocated Sector Count
Reallocated Event Count
Current Pending Sector
There was a message prompted in my screen that my HDD has a problem, and it needs to be backed up immediately so I tried to test it.
Does it mean I have to replace my HDD with a new one or just reformat it first for the meantime?
