So you probably know organisms carry DNA, which is basically a set of instructions for how to build and operate the body. The nucleus of every cell carries the genome, which contains those genes, as well as a lot of other stuff.
Genes are made up of sections called exons and introns, as explained in the video. The exons are made into RNA, which is used by the cell to make proteins. The introns have to be removed from the genomic sequence before that can happen. So if we don’t need those introns, why do we have them? For one thing, it allows the cell to make different genes from the same genomic sequence. The introns themselves may also serve a purpose.