Mastering Rust - Second Edition

Ownership

The notion of a true owner of a resource in a program differs across languages. Here, by resource, we collectively refer to any variable holding a value on the heap or the stack, or a variable holding an open file descriptor, a database connection socket, a network socket, and similar things. All of them occupy some memory from the time they exist until the time they are done being used by the program. An important responsibility of being the owner of a resource is to judiciously free the memory used by them, as not being able to perform deallocations at proper places and times can lead to memory leaks.

When programming in dynamic languages such as Python, it's fine to have multiple owners or aliases to a list object where you can ...