What are the different stages of skin cancer?

Depth and metastasis. In melanoma the stage is dependent on the depth of the primary tumor, the prescence of ulceration and mitoses, and whether the cancer has spread to lymph nodes or distant organs.
Generalized answer. There are many different types of skin cancer and therefore there' is no one answer but most cancers have several stages speaking in general terms and these fall into premalignant with atypia, in situ, early, advanced, invasive, and metastatic. Furthermore most cancers will be staged by the tnm classification.