accessible

easy to reach or understand

Roots

-able / -ible: able to be, fit to be, or worthy of
ced / cess / ceed: go, approach, yield, move back, or stop

Other words with the ced / cess / ceed root

cease: to stop
cede: to yield or give up control
concede: to admit or yield
incessant: continuing without stopping
intercede: to plead or act on behalf of another
precede: to come before
precedent: an earlier example that guides later cases

Accessible means there is a way in: the person, place, idea, or price can be reached.

The teacher made the abstruse proof accessible with one diagram.

Access is approach. Accessible adds -ible: able to be approached, reached, or understood. Keep the contrast with recede: one opens a way in; the other pulls away.