whats the difference between these type of targe ID's?

Without knowing the detector model I'd say it has 99 target ID segments which means the numeric display ranges from 1 to 99. Thats not bad and generally I'd say comes on your mid to higher end detectors. Target ID segments fall in to ranges to help determine what a target might be. For example a clad dime may have a Target ID of 79 to 82. That would be Target ID segments. Generally, the more segments the more accurate your detectors Target ID might be.

The audio could also be segmented(tone ID) to give a different tone depending on the numeric value. Real handy so you don't spend a lot of time watching the display. You can just listen for the higher tones. Good for cherry picking.