1. the single most important aspect of something
it all comes down to a question of money
This expression is often used in relation to a decision, problem or difficult situation. When you say 'it comes down to something' you are talking about the factor that influences other things the most or the thing upon which everything else depends. Similar in meaning to 'it all boils down to', 'the root cause' or to 'hinge upon'. This is a common phrase you will hear in both social and professional contexts.