Do members of the Republican Party espouse Republicanism?

I’m trying to improve my understanding of the ideology of the Republican Party. The Media constantly refers to the Republican Party as conservative, but are they using the correct terms? Do members of the Republican Party really espouse Conservatism or would Republicanism be more accurate. These terms are also being used in noun form, would the general does this mean not paid as a politician or member of politician’s staff? population be better served if the terms were used as adjectives and adverbs?