Scale degrees are the notes/members of any scale. Each note/member gets a number called a degree. It starts with 1 then goes on from there. I'll give you an example using the C major scale:
C D E F G A B
There are seven members, they each get a number from 1-7 like this:
C = 1
D = 2
E = 3
F = 4
G = 5
A = 6
B = 7
You could stop there, or you could keep going:
C = 8
D = 9
E = 10
F = 11
G = 12
A = 13
B = 14
You get the picture?
