Look at a sponge. It seems to be solid, right? But what happens when you squeeze it? It gets smaller! Why? If you look closely at the sponge, you will see that it has lots of holes in it. The sponge is actually made up of a mixture of solid and gas. When you squeeze it, the solid part changes its shape but stays the same size. The gas in the holes reduces and the entire sponge takes up less space. Images and Videos are like sponges! There's lots of data that does not carry information, and we can remove it. This short session helps everyone understand why we use compression, what are the fundamental quests we try to solve, what are some of the fundamental concepts used by video codecs (starting from the basics), and some of the latest trends.