Footings are structural members that support columns and walls and transmit their loads to the soil in a way that does not exceed the soil's load bearing capacity or cause excessive settlement. There are different types of footings including isolated, combined, cantilever, continuous, rafted, and pile caps that are used depending on the column layout and soil conditions. Properly designing footings involves determining loads, allowable soil pressures, footing sizes, settlements, and other factors according to code requirements.