Computing resources are used by computer programs during execution.  The resources include disk space, memory allocation, network bandwidth, and processor cycles.  Modern computers are designed to enable multitasking—the sharing of a single resource among multiple processes. 
Distributed computing is an architecture that pools computer resources across multiple computer machines to carry out a single or multiple related processes.  Computer code may be specially designed to be split, or can be executed by other code that is designed to split the executing code, across multiple computer machines, a feature sometimes called parallelization.