AI is an acronym for Artifial Intelligence.
It is a broad covering definition of the concepts that may make a machine appear to be or actually be behaving intelligently.
There are many techniques which fall under this banner
Natural Language Processing
A system does not necessarily have to learn to be considered AI, although it is considered closer to being truly intelligent behaviour if it can learn.
Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.