The word Digital is derived from the Latin digitus which means finger. Typically when we do simple arithmatic equations we use a base ten system. This is because human beings have ten fingers and it is easiest for us to think in terms of sets of ten. Most modern computers use a binary or base two system. All code in a binary system is based on 0's and 1's. If the first computers were our fingers and our use of them to carry out addition and subtraction, the first external computer was the Abacus. The oldest known use of the Abucus was by the ancient Summerians.

The Antikythera mechanism

In 1900, a storm blew a boatload of sponge divers off course and forced them to take shelter by the tiny Mediterranean island of Antikythera. Diving the next day, they discovered a 2,000 year-old Greek shipwreck. Among the ship's cargo they hauled up was an unimpressive green lump of corroded bronze. Rusted remnants of gear wheels could be seen on its surface, suggesting some kind of intricate mechanism. The first X-ray studies confirmed that idea, but how it worked and what it was for puzzled scientists for decades. Recently, hi-tech imaging has revealed the extraordinary truth: this unique clockwork machine was the world's first computer. An array of 30 intricate bronze gear wheels, originally housed in a shoebox-size wooden case, was designed to predict the dates of lunar and solar eclipses, track the Moon's subtle motions through the sky, and calculate the dates of significant events such as the Olympic Games. No device of comparable technological sophistication is known from anywhere in the world for at least another 1,000 years. So who was the genius inventor behind it? It is beleived that Archimedes invented the device but was killed by invading Roman troops before it's use could be uncovered.

During WWII the Nazis used a code machine known as the enigma machine. It used a set grouping of letters and numbers that required the same setting at the other end to decipher codes. For nearly a decade the enigma code remained, appropriately, a mystery.

In order to crack the German code the Americans and  British combined forces to build the Colossus computer (1943). It had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically re-programmable.The Colossus took up an entire warehouse and required a team of engineers to operate yet it had less computing power than a cheap digital watch today. It was used to help finally decipher the enigma code and thus give the allies the ability to listen in on the axis' military plans, drawing an end to the war.

Apple Computers developed their first desktop computer in their parents' garage, and sold the first Mac for 600$. Below is an image of the device as it was patented in 1976.

A hard drive (HDD) is a data storage device used for storing and retrieving digital information. An HD retains its data even when powered off. Data is read in a random-access manner, meaning individual blocks of data can be stored or retrieved in any order rather than sequentially. 

The Motherboard (sometimes alternatively known as the mainboard, system board, or colloquially, a mobo) is the main printed circuit board (PCB) found in computers and other expandable systems. It holds many of the crucial electronic components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals.

A central processing unit or CPU, is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. The term has been in use in the computer industry at least since the early 1960s. The form, design, and implementation of CPUs have changed over the course of their history, but their fundamental operation remains much the same.

Software refers to any actual code or set of machine-readable instructions (most often in the form of a computer program) that directs a computer's processor to perform specific operations. 

System software is computer software designed to operate and control the computer hardware and to provide a platform for running application software.

Programming software includes tools in the form of programs or applications that can accomplish specific tasks.

Digital Cameras

Steven Sasson as an engineer at Eastman Kodak invented and built the first electronic camera using a charge-coupled device image sensor in 1975. Earlier ones used a camera tube; later ones digitized the signal. Early uses were mainly military and scientific; followed by medical and news applications. By the mid-2000s digital cameras had largely replaced film cameras, and higher-end cell phones had an integrated digital camera.

CMOS Imaging Sensor

A CMOS imaging chip is a type of active pixel sensor made using the CMOS semiconductor process. Extra circuitry next to each photo sensor converts the light energy to a voltage. Additional circuitry on the chip may be included to convert the voltage to digital data.

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