Capitalism is free trade. For capitalism to exist, you must a right to private property and free association. In capitalism, you generate riches by producing and trading it for something of greater value to yourself. The person acquiring your product is giving you something that you want in exchange for something that they want. Both sides win. In capitalism, the one that is always above everything else is the consumer and the consumer dictates the market rules most of the time. Once the consumer finds a different product that is cheaper and has the same function that yours have, you will have to step up your game. This competition in the free market is what boosted most of the technology and quality of things that we have around us today. Everybody wants to pay less for something even better.
In socialism, there's a worry about the less favored parts of society. To be able to take care of them, governments take part of the money of the workers and producers to invest in measures to assist the less fortunate. Much of this process is called "income distribution". To many, socialism is a middle way to communism, where everybody is supposed to be the same and have the same no matter what.
