Definitions for "academic session"
the time during which a school holds classes; "they had to shorten the school term"
is ‘owned' by terms; for instance, the Spring term has within it the Spring, July, August and Summer sessions. Sessions may overlap but terms may not.
The fall/winter period from September through April or the spring/summer session from May to August. Both sessions are composed of two terms. Full-credit courses generally run for a complete session while most half-credit courses are for a single term only.