Shari, others with more experience can explain this better- but here's my layman's interpretation:
Axis 1 is clinical diagnosis
Axis 2 is personality stuff (not sure- maybe personality disorders)
Axis 3 is any physical health contributors
Axis 4 are stressors or other contributing difficulties (my son's lists getting into trouble at school, memorization issues)
Axis 5 is GAF which is some scale measuring level of functioning or something like that- 100 being the best; 0 being the worst. So, when my son is stable and he's evaluation'd, his gaf would be high- maybe 90- but when he's unstable it would be low- maybe 50 or something. Anyway, this varies and if it's high, others (sd, profs, etc) are likely to tell you that whatever supports/medications he's getting are working; if it's low, you have grounds to say he needs more help