Grafting is joining the stem or bud of one plant onto the root or stem of another to form a new plant and graphing is a feature in some software program that allows numerical data to be interpreted as a graph or chart. Grafting is the right word in the sense of planting. Graphing is not the appropriate word for it.
No, depending on where you live, you do not need to graft the avocado seed/plant to another plant. It will take a long time for the tree to reach a suitable age for fruit though. If you live in a colder region, I would not even attempt growing avocados. Grafting as he said above is typically taking the trunk/branch from one tree and wiring it to another type of tree to get a type of hybrid. For instance the white pine does not live well in lower altitudes, so it is often grafted to the root/trunk base of a black pine that can handle lower altitudes and warmer weather.
Grafting is like in skin grafts, graphing would be like graphing some type of information