The movement (of someone or something) forward followed by a return to the same position. May refer to a concept such as an emotional state or a relationship as well as a physical thing.
Going from one place or position to another and back again.
moving from one place to another and back again
"he traveled back and forth between Los Angeles and New York"
"the treetops whipped to and fro in a frightening manner"
"the old man just sat on the porch and rocked back and forth all day"
From one place to another and back again.