Have you noticed how, as time goes on and technology advances, things seem to keep getting smaller and smaller? That’s especially true with that machine we call the “computer.”

What exactly is a computer? That’s not always an easy question to answer.

Merriam-Webster’s Collegiate Dictionary defines a computer as “a programmable usually electronic device that can store, retrieve, and process data.” Others think a computer is anything that transforms information in a meaningful way.

For thousands of years, people have tried to improve their lives by inventing machines to make certain tasks easier. Some people believe a simple mechanical device called an “abacus” was one of the earliest forms of a computer.

Ancient peoples used the abacus to perform simple calculations. Archaeologists have found evidence that the ancient Greeks used the abacus as early as the 5th century B.C.

“Modern” computers were developed much more recently. The first modern electronic computer — known as the Electronic Numerical Integrator and Computer or ENIAC — became operational in 1946.

ENIAC was created for the U.S. Army. Weighing more than 30 tons, ENIAC took up as much space as some houses (1,800 square feet).

Since ENIAC, computers have become much smaller and much more powerful. While ENIAC could perform 5,000 addition problems per second, many of today’s laptop computers weigh just a few pounds and can perform several billion operations per second.

As powerful as they are, modern laptops are slow compared to modern supercomputers. A new Titan supercomputer being built for the U.S. Department of Energy is set to become the world’s fastest computer. Its creators claim it will be able to perform 20,000 trillion calculations per second.

Today, we rely on computers for all sorts of things. Parents routinely use computers at work. Kids use computers in the classroom. Many homes now have multiple computers.

Today’s computers keep getting smaller and smaller. Large desktop computers gave way to laptops. Laptops have evolved into a wide variety of even smaller computing devices, such as netbooks and tablet computers.

Many people even carry computers with them everywhere they go. Do you know someone who owns a smartphone?

Smartphones — cellular telephones with advanced computing capabilities — fit easily into a pocket and allow their users to make telephone calls, surf the Internet and conduct business on the go.

So what’s the smallest computer available today? It’s right around the corner.

Today’s computer manufacturers are constantly producing newer and smaller models at a rate too fast to keep up with. Whatever is smallest today will probably be replaced with something even smaller tomorrow!