Biopsies (11100 series) are for taking a sampling or portion of the lesion for diagnositc purposes (usually 88304 or 88305 path codes). Often these are taken using a punch or partial removal with a blade (biopsy via shave technique).
The 11300 series are shave removals and are coded based on size of the lesion removed. Generally the lesion is removed "in toto" using a shave technique (thin blade to scoop out lesion) without full-thickness dermal ecision. These are generally still sent off for final path to confirm that the nature of the lesion and that margins were clear. Usually no repair is needed.
Some definitions...
Shave removal - Shaving is the sharp removal by transverse incision or horizontal slicing to remove epidermal and dermal lesions without a full-thickness dermal excision. This includes local anesthesia, chemical, or electrocauterization of the wound. The wound does not require suture closure.
Excision - Excision is defined as full-thickness (through the dermis) removal of a lesion, including margins, and includes simple (non-layered) closure when performed.
The difference is based on intent and how deep you go.
Biopsy = Sampling only of representative tissue
Shave removal = Removal via shave technique without full-thickness dermal excision
Excision = Full-thickness removal of lesion including margins