1.conjunctionConnects at least two alternative words, phrases, clauses, sentences, etc. each of which could make a passage true. In English, this is the "inclusive or." The "exclusive or" is formed by "either [...] or".
"He might get cancer, or be hit by a bus, or God knows what."
2.conjunctionAn operator denoting the disjunction of two propositions or truth values. There are two forms, the inclusive or and the exclusive or.
3.conjunctionCounts the elements before and after as two possibilities.
4.conjunctionOtherwise (a consequence of the condition that the previous is false).
"It's raining! Come inside or you'll catch a cold!"