Capitalism is an economic system that favor capital (ownership) over labor (people) and land (the environment) because capital formulation generates growth and "a rising tide lifts all boats" (trickle down).
Socialism is an economic system that favors labor (people) and land (the environment) over capital (ownership) because the economic system is the life-support system of society and needs to be subjected to the comprehensive needs of society, which are social and political in addition to economic.
In addition, contemporary "capitalism" is economically inefficient owing to socialization of negative externality and rent extraction facilitated by asymmetries. These asymmetries are social (class structure privilege the ownership class that results in social unrest), political (wealth translates into political power resulting in oligarchy), and economic (income and wealth inequality that result in maldistribution masquerading as "just deserts."