2. What is the difference between encaustic and fresco painting?

The difference between encaustic and fresco paintings is one of mediums. Encaustic paintings are made using pigments that have been mixed with hot, melted wax. Generally, this paste is then applied to a wood or canvas surface. Encaustic paintings are generally associated with Ancient Egyptian mummy portraits.
A fresco, on the other hand, is a kind of wall painting, or mural, done on wet lime plaster with a water-based pigment. The paint and the plaster dry as one, such that the painting literally becomes a part of the wall. Frescos are most commonly associated with the Italian Renaissance, with world-famous examples by Michelangelo in the Sistine Chapel, though they have been around for much longer than that (although few from antiquity have survived).