What do the words company and companion have to do with bread?

The words company and companion come from the latin ‘com’ meaning with and ‘pan’ meaning bread. So a companion is someone you eat or share bread with.

c. 1300, “one who accompanies or associates with another,” from Old French compagnon “fellow, mate, friend, partner” (12c.), from Late Latin companionem (nominative companio), literally “bread fellow, messmate,” from Latin com “with, together” (see com-) + panis “bread,” from PIE root *pa- “to feed.”

Online Etymology Dictionary