Exome sequencing means that all protein-coding genes in a genome are sequenced. In Humans, there are ~180,000 exons that makes up 1% of the human genome which contain ~30 million base pairs. Mutations in the exome have usually a higher impact and more severe consequences, than in the remaining 99% of the genome. With exome sequencing, one can identify genetic variation that is responsible for both Mendelian and common diseases without the high costs associated with whole-genome sequencing. Indeed, exome sequencing is the most efficient way to identify the genetic variants in all of an individual's genes. Exome sequencing is cheaper also than whole-genome sequencing. For training on exome sequencing data analysis, the Galaxy community proposes two tutorials (https://github.com/bgruening/training-material/tree/master/Exome-Seq). Here, you can find the needed datasets for these tutorials.