The ancient Egyptians mummified the bodies of the dead. Why was this done?

The ancient Egyptians believed that after the death of a person, an afterlife awaits. In order for a person’s soul to live happily in another world, it was necessary to preserve his body as best as possible. Therefore, the Egyptians mummified the bodies of the dead and left in their tomb various things that they liked to use during their lifetime. Sometimes they even mummified the deceased’s favorite animals (in particular cats) so that they never parted.