Is mexican and spanish the same or two different languages?

Well Latin American spanish is slightly different in some words maybe best way is to say a different dialect but basically the same

yeah the same

"Mexican" is not a language. Mexican is referring to what someone is. A person from Mexico is considered a Mexican. Just like a person from American would be considered an American.

Mexican is not a language, but in Spain and Mexico the Spanish is different

Mexican isn't a language, this is the way people from Mexico are called. Spanish is the language used in Latin America, espacially Mexico.

They are different in the same way that the English spoken in England is different from the English spoken in American. There are a few different words, but a Spaniard from Spain will understand 99.9 percent of what a Mexican says.
See the article below to see how much difference there is between British and American English.

The Spanish spoken in Mexico has some slightly different pronunciations and a wealth of slang when compared to Castilian Spanish that is taught in U.S. H.S or spoken in parts of Spain. The Spanish spoken in Mexico is also peppered with words from the various indigent peoples, many of whom still speak their own languages as well.