A parallel computer is a computer whose architecture utilizes multiple processing elements, such as CPUs (central processing units) or cores, to perform computations simultaneously. Unlike traditional sequential computing, where a single processor executes one instruction at a time, parallel computers divide tasks into smaller parts that can be processed concurrently. Essentially, a parallel computer can work on different parts of a shared set of data at the same time.
Using parallel computers reduces the time it takes to complete a task and improves overall performance. To make an analogy, a parallel computer is like having many chefs in a kitchen working on a food order. Each cook prepares a different dish at the same time to serve the complete meal quicker. Or, for another example, consider a large order of the same meal, such as 1,024 cheeseburgers. Each chef (CPU or core) may perform the same task: grilling the burger, melting the cheese, etc., so that all cheeseburgers are ready to eat at the same time.