In capitalism, the rights and interests of individuals are primary, while the rights of the state (with the small “s”) are secondary. They are derived from the interests of the individuals and their scope is limited. Civil rights may be restricted only under exceptional circumstances, such as a war. The income may be taxed on the grounds of the necessity to fund the basic functions of the state: the defence, the security, the judiciary, and the basic public services. Property may not be confiscated; only when it's absolutely necessary, the owners must obtain an adequate indemnification.
In socialism, the rights and interests of the State (with the capital “S”) are primary. Individuals have the obligation to obey the State in the name of the common good. The human and civil rights are considered as privileges that are not inalienable and natural. The rights are lent by the state to its subjects and may be suspended whenever the State deems appropriate. Property and income is also considered as something that is only lent to the individuals, and the State has the right to confiscate as much of it as it needs at any time.
In short, capitalism is based upon individual efforts, individual responsibility, and individual rights. The state is considered to be merely a service organisation akin to facility management or a concierge. It works on behalf of the owners who live in the house. The socialist state, however, is not a service organisation, but a cult or a sect, which owns the house and the tenants.
Socialism is based upon the belief in the “common good”; it's the State who defines it and who enforces the allegiance to it. Capitalism needs no ideology other than the free market. Socialism, however, always needs an ideology to define the object of the common worship and to justify the broad scope of the power of the State. Socialism without an ideology is unthinkable.
On the other hand, capitalism is not an ideology, but just an economic system. It has worked in democracies and in dictatorships, in republics and in monarchies. Capitalism built the wealth of America as well as of Switzerland and Sweden (until the introduction of confiscatory tax rates in the 1970's.)
While socialism is an artificially conceived idea, capitalism was never invented by somebody. It just emerged in the course of the human history as a normal, generic system of organising the society. It is not perfect, because the human nature is not perfect, either. Nobody has ever claimed that. How does socialism compare? Not quite well, I'd say.