The art criticism process is actually quite simple. When you are critiquing an art piece it could be difficult, but really its just looking at all the little things in the piece. You don't have to look at the fact if it all goes together nicely, just looking into the art and "reading in between the lines" of art.
1. What is art? In my opinion there really isn't an answer to that question. There is so many different types of art and varieties, and different people like different things in art. Some person may think that art isn't really that interesting and couldn't really care a whole lot for it. Other people might think that art is the most amazing thing that man kind could create. In my opinion art is feelings and thoughts put on a piece of paper without using words. Art could tell you a lot of things if you could read what its saying.
4. What are some reasons that artist make art? I couldn't answer that question for every artist out there, but I would think the reason that they make art is to express the things that are inside of them that they cannot put into words. Or, sometimes, art makes people happy, so they might just like seeing/making a stranger smile. Knowing that they are the reason that they are smiling.
5. What is an artistic style? An artistic style is the way an artist does his/her work. Most artist have a theme to their work, so that theme is their style of art. With their styles they mostly make all of their art the same way just with different story to it everytime.