Explain Baudrillard's theories of advertisement and simulation.

Baudrillard's simulation argument focuses on the role of maps and models in our lives and how these have become paramount to our perceptions of reality. Basically, Baudrillard is saying that we have come to rely on models so much that these have become reality and precede the natural world. We can posit several different examples of this, but video games are probably the easiest to understand.
If you look at a game such as Grand Theft Auto, Baudrillard would say that people are totally engrossed with everything going on in the game to the exclusion of anything else. They come to believe that the actions by characters controlled by other online players are as real as if they actually happened. It is as though the simulation of real life has replaced real life experiences.
In terms of advertising, Baudrillard argues that the media manipulates individuals' desires according to the media's objectives (selling products and making money). Advertisements are thus a means by which corporations shape individuals' wants and demands; individuals do not determine what corporations make through free exchange on the open market. Baudrillard is therefore saying that the open market is not open because individuals are not choosing what to buy, but they are buying what media and corporations have convinced them to buy.
There are a lot of criticisms of Baudrillard's work, as with postmodernism generally—perhaps the most crucial being his subjective interpretations that are posited as fact. Postmodernism rejects objectivity and the scientific method (although they still use words such as "theory"). And similar to many other postmodernists, Baudrillard's work has been highly criticized for being purposefully obscure. He makes interesting points, but it also seems as though these points are intentionally placed in a fog of academic jargon in order to give them greater validity.
https://plato.stanford.edu/entries/baudrillard/