Profit is the Revenue(all of the money that you get from selling the products) - all of the costs; so that includes, manufacturing costs, Labour costs, overheads, tax costs, marketing, transport/distribution, insurance, rent, etc.

Companies can increase their profits in a number of ways, but in simple terms they can either reduce their outgoing costs or increase their incoming revenue. Most of the time they try to do both. So they might be putting fewer of their products in each box but charging more for them, or reducing the quality of their packaging but charging more for the products, laying off employees but charging more, or dodging taxes but charging more etc. etc.