What is a Computer?

Introduction

Computers, programs, and algorithms are three closely related topics that deserve special attention before you start learning about Java proper. Why? Simply put, computers execute programs, and programs implement algorithms. As a programmer, you will live your life in the world of computers, programs, and algorithms.

As you progress through your studies, you will find it extremely helpful to understand what makes a computer a computer, what particular feature makes a computer a truly remarkable device, and how one functions from a programmer’s point of view. You will also find it helpful to know how humans view programs, and how human-readable program instructions are translated into a computer-executable form.

Next, it will be imperative for you to thoroughly understand the concept of an algorithm and to understand how good and bad algorithms ultimately affect program performance.

Finally, I will show you how Java programs are transformed into byte code and executed by a Java virtual machine. Armed with a fundamental understanding of computers, programs, and algorithms, you will be better prepared to understand the concepts of the Java virtual machine as well as its execution performance and security ramifications.