What is Ideology?
In my view, ideology is a concept of an economic or political theory which is a set of ideas, beliefs, values and principles that reflects understanding of the social world which shapes decisions.

Example of Ideology
An example of ideology is socialism. Socialism is an economic and political system where the state owns and controls the means of production. Its goal is to seek inequality by measuring out among the population by economic planning to provide basic needs.

Difference between conservative & liberal ideology in US politics
>Liberal ideology is individual rights, equality and liberty therefore, advocates or supporters of a political philosophy. Liberals believe that the government can help solve problems, support government intervention in the economy such as regulations and higher taxes therefore, government protecting the environment

  >Conservative ideology values tradition and strong nation identity which limits government intervention therefore, favor policies such as lower taxes and private ownership. 

Example
Conservative are people who favor free enterprise and socially traditional ideas. Also, promotes nuclear family organized religion and property rights. It’s more of a gradual change to maintain social order. Whereas, liberals believe everyone should be treated the same way. Liberalism separation of powers into different branches of government, a separation of religion from the government and freedom of speech.

Althusser’s Ideology
The analysis of Louis Althusser institutions such as the educational system, churches, etc exist to reproduce capitalist relations of production and maintain order in society. Therefore, education helps to control the masses.