A asymmetrical (you cannot draw a line through the middle)
B border. The borders of the spot are irregular
C color. The colors of the spot is uneven.
D diameter. The spot has a diameter the size of a pencil
eraser.
If you have a spot on your skin that has the A B C D of melanoma go to the doctor now.
You betcha.
Mine looked like someone drew a cartoon of a mole on my leg. Way too festive looking. I watched it for 20 months like a moron until I couldn't ignore that it was getting larger. It was the type called superficial spreading. It hadn't gone too deep. Removed 8 years ago with no recurrence. I say that crossing my fingers and without smugness.
If you have something on your skin giving you any questions whatever, get your ass to the doctor, now.
Also,
E elevation. The spot is smooth with the skin, not bumpy or raised.