Juxtaposition, Merriam-Webster.com
Noun
Etymology: Latin juxta near + English position — more at joust
Date: 1654
: the act or an instance of placing two or more things side by side; also : the state of being so placed
Example: I followed a post on how I hate the Post Office with a post on our lesson, which was all about love.
Notes from Aunt Gem 