sects / sex 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. 👇
sects: (noun) a subdivision of a larger religious group.
sex: (noun) either of the two categories (male or female) into which most organisms are divided. (noun) all of the feelings resulting from the urge to gratify sexual impulses. (noun) the properties that distinguish organisms on the basis of their reproductive roles. (verb) tell the sex (of young chickens).
sects: s·EH·k·t·s
sex: s·EH·k·s
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)