Communism: People have no say in the government. The government controls the social and cultural life of people.
Democracy: People choose their leaders. Laws are framed to protect the civil rights of the people.
Communism, as a political and economic ideology, aims to create a stateless and classless society, where everyone is equal. To achieve this, the state becomes the one who owns all factors of production (labor, entrepreneurship, capital goods, natural resources). Though this form of control is meant to benefit people through more social and economic equality of opportunities, it ends up controlling the social and cultural life of people as well as limiting people's says over the government, and social and economic policies.
Democracy is a political system, in which people choose and replace government through free election. This form of government is characterized for the active participation of the people in politics and civic life, and the protection of the human rights of all citizens.