Overall there are 5 stages of cervical cancer and within each stage are different gradations.
The five basic stages are:
Stage 0 is when the cells are just on the
surface of the cervix and have not entered the tissue deeper.
Stage 1 the cancer has grown into the cervix but hasn't gone beyond the uterus and is not in any lymph tissue.
Stage 2 the cancer has gone beyond the cervix and uterus and maybe into the upper part of the vagina, but not the lower part or the pelvic walls
Stage 3 the cancer has spread into the lower part of the vagina or the pelvic walls but is still not in the lymph nodes. Although later grades of stage 3 can involve the lymph nodes.
In stage 4 the most advanced stage, it has spread to nearby organs.
This really detailed page from the American Cancer Society explains all of the levels within each stage.