Computers can be classified on different bases. They can be classified on the basis of their way of processing data, size, model etc. Today, we are going to classify computers on the basis of data processing. According to the way, computers process data, they can be categorized into three groups which are:
1. Digital Computers: Digital computers are such computers which process discrete data in binary form (i.e. 1 and 0). These computers require some entity to represent numbers. The representation is not a simple one-to-one relationship. It is determined by a kind of algorithm which is called the binary number system. This algorithm transforms a number/character into a sequence of 0’s and 1’s internally in the computer. The accuracy of digital computer is only limited by the size of registers and memory. Letters, words etc. are also coded in binary form. Digital computers almost have an unlimited memory and potentially much higher accuracy since they do not depend upon physical quantities for processing.
2. Analog Computers: The computers that process continuous data (values or quantities) are known as analog computers. The computations or calculations are carried out with the help of different physical quantities like voltage, current, air pressure, linear distance, temperature, velocity of rotating shaft etc. Analog computers use some sort of analogue or analogy like Ohm’s Law so as to affect a solution. They are used mostly in controlling devices in some continuous processes. Since analog computers use some physical analogue for representing numbers, they can often avoid time consuming arithmetic. However, they cannot perform logical operations because they have minimal memory. Likewise analog computers can never be absolutely accurate because physical quantities are always difficult to measure precisely and they tend to fluctuate somewhat with the change in conditions like temperature, humidity, degree of wearing and so on.
3. Hybrid Computers: The word ‘hybrid’ simply refers to a new breed which has been created by the combination of two or more different breeds or species. In case of computers, hybrid computers can be defined as such types of computers which are especially designed by combining the best features of both analog as well as digital computers. They use both digital and analog components so as to process continuous as well as discrete or digital data. They can convert data from analog to digital and from digital to analog as well. They can do so with the help of Analog to Digital Converter (ADC) and Digital to Analog Computer (DAC). These computers have the speed like that of analog computers and accuracy like that of digital computers. These types of computers are especially used in different institutions like hospitals, weather forecasting centres etc. In hospitals, the analog part of hybrid computer is used to measure the heartbeat, blood pressure, temperature and other vital signs of a patient and digital part of that is used to monitor the patient’s vital signs.