cession / session are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
cession: (noun) the act of ceding.
session: (noun) a meeting for execution of a group's functions. (noun) a meeting devoted to a particular activity.
cession: NA
session: s·EH·sh·ah·n
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)