Difference Between Analog and Digital Computer

Computers have become an integral part of our day-to-day life. We cannot imagine our lives without computers. We use computers for almost all our daily activities. At present, everyone is familiar with digital computers like smartphones, digital watches, laptops, desktop PCs, etc. But there is another variant of computers called analog computer. Analog computers are the earlier variants of computer that are less frequently used these days or used in some specialized applications only.

Read through this article to find out more about analog and digital computers and how they are different from each other.

What is an Analog Computer?

A computer that operates on continuous-time signals, i.e. takes input and produces output in the form of signals that vary continuously with time is called an analog computer. Analog computer is the oldest variant of the computer that we use today. These computers were very common during the 1950s to 1960s.

Analog computers are less efficient, less reliable, slow speed computers. These computers can store a small and limited amount of data and information. Analog computers require understanding of signal processing and scientific knowledge to use them, thus they are used in specialized applications.

What is a Digital Computer?

A computer that operates on the discrete-time signals (or discontinuous-time signals) is called a digital computer. A digital computer is built up of digital electronic devices like logic gates, digital ICs, transistors, etc. These computers use the binary number system to perform their calculations and other operations.

A typical digital computer accepts input in the form of digital signals (binary signals, in the form of 0s and 1s), processes them according to user’s instructions, and finally produces the results in a user readable form using a digital display screen.

The first digital computer was designed during 1940s for basic numerical calculations and has made many advancements in the field computing technologies over the years. Digital computers are more accurate, efficient, reliable, and easy to use. For these reasons, they are widely used in a large number of applications.

Difference between Analog Computer and Digital Computer

The following table compares and contrasts the important features of analog and digital computers −

Parameter Analog Computer Digital Computer
Definition A computer that works on continuous-time signals is called an analog computer. A computer that works on discrete-time signals is called a digital computer.
Speed The speed of such computers is less than that of digital computers. The speed of digital computers is more in comparison to analog computers
Memory Capacity Analog computer has very less memory, and can store limited amount of data. Digital computer has more memory space, hence stores large amounts of data
Switching States Analog computer doesn’t have any state because the variation in signals is continuous. Digital computer has two switching steps: On and Off.
Reliability Analog computers are not as reliable as digital computers. Digital computers are more reliable.
Performance Analog computer doesn’t provide performance as good as digital computers. Digital computer provides great performance.
Processing Speed The processing speed of an analog computer is low. The processing speed of a digital computer is high.
Dependency on Physical Changes The operation of analog computers depends on physical variations. The operation of digital computers doesn’t depend on physical variations.
Accuracy The results given by analog computers have very less accuracy. The results produced by digital computers are more accurate.
Ease to Use Analog computers are not easy to use. Digital computers are easy to use.
Complexity of Architecture Analog Computers have a complex architecture. The architecture of digital computers is not as complex as analog computers.
Readability Analog computers have low readability. Digital computers have high readability.
Output Method The results of analog computers are given out as voltage signals and are difficult to read and understand. The results of digital computers are displayed on the monitor/display screen.
Encoding Technique Analog computers use analog encoding technique. Digital computers use digital encoding technique.
Device type Analog computers are used as special purpose devices. Digital computers can be used as a general purpose device.
Power Consumption Analog computers consume more power. Digital computers consume less power.
Examples Examples of analog computers include analog clock, analog energy meter, analog speedometer, thermometer, etc. Examples of digital computers include laptop, digital camera, digital watches, smartphones, PDAs, etc.


To conclude, digital computers are more popular over their analog counterparts. However, there are some special areas where analog computers are still being used. But for general purpose applications, digital computers are unbeatable.