How do subsistence and cash crops differ?

In subsistence farming, planting decisions are made based on a family's needs, whereas in cash-crop farming, farmers plant strategically to capitalize on demand and market prices. While some farmers grow crops for the sole purpose of feeding their families, others engage in both cash crop and subsistence farming.

Subsistence farming, is growing crops based on a family's needs. If a family has 6 members they will grow the right amount to feed 6 people. Cash crops are where people grow extra so they can make money of the crops. Let's say they also have 6 people to feed, they grow enough for 6 people plus a lot more, they sell it to make money