What is the difference between ANSI C and C plus plus?

C is a programming language and ANSI is the standardization committee. The C language is under the auspices of the ANSI committee, which monitors the grammar and structure of the language in a standard way that compiler writers must adhere to.

ANSI C means that it is a standardized version of the C language according to the rules of the committee and should work/compile the same way on any system that uses an ANSI C compliant compiler.