Difference between between AVE and RENFE

Dick,

Renfe is the acronym for 'Red Nacional de Ferrocarriles Españoles', it's the National Network of Spanish Railways.
AVE = (Alta Velocidad Española) = a high-speed train that connects many of the cities in Spain & it's operated by Renfe.
{AVE also means 'bird' in Spanish}

In short, RENFE is a train operator... AVE is a type of fast speed trains (which is operated by RENFE)

AVE is the high speed train. Renfe is the train company. Take an AVE if you can between cities as it is a great experience.

Read this article for the best information on everything you need to know about the trains in Spain.