There are many types of operating systems. Every time we are interacting with a machine, a different type of operating system is helping us do that. It is important to know that most of the time an operating system may overlap with a different type of operating system. Like, an embedded system OS may also use some features of a real-time OS.
Mainframe Operating Systems
These computers are those elephant sized machines found on major corporate data centers. A mainframe system has huge specifications and is generally used for tons of input output operations done together.
It requires an operating system that is different from what we use everyday for this purpose.
Generally speaking, a mainframe system offers three kinds of services: batch, transaction processing, and timesharing.
Batch System: This is a type of system that processes routine jobs that doesn’t need any user to be present. For example, reporting sales in a large store like Walmart.
Transaction Processing: This deals with handling a large number of small requests together. For example, airline reservations.
Timesharing: This allows multiple remote users to work on the computer at the same time. For example, running queries on a large database.
Server Operating Systems
Server operating systems are still high-end, but a level lower than mainframe systems. This type of operating system powers up servers that can serve multiple users over a network and allow the user to share software and even hardware resources.
A common example of a server system can be seen in a computer lab, where all systems are connected to a common server and all the computers are connected through a LAN setup.
Personal Computer Operating Systems
Barely any introduction is needed to this type of operating system as this is the most common type of it. In fact, users think that this is the only type of Operating System.
Your laptops and desktops are personal computers that run this type of Operating System.
The three popular Operating Systems for personal computers are Windows, MacOS and Linux.
Handheld Computer Operating Systems
Before phones became smarter, there was a handheld system commonly referred to as Personal Digital Assistant (PDA). These were really popular with businessmen.
Palm OS was the common standard for PDAs. This was before Windows optimized itself for Pocket PCs and definitely before iPhones.
The handheld systems include smartphones and PDAs, though they have become obsolete now. The common Handheld Computer Operating Systems are Android, iOS, and Windows.
Embedded Operating Systems
This type of operating system generally doesn’t strike as a computer. Embedded systems are present in Microwave Ovens, tape recorders, radios, televisions, cars and any other electronic thing you can think of that’s not a computer.
The entire software is installed in a ROM chip and so it can be certain that no untrusted software will ever be installed on it. It can however go through a software patch via a cable.
Modern day embedded systems equipped with WiFi chips can also be updated via internet.
For more detail on Embedded Systems, you can take a look at this free Embedded Systems Course.
Real-Time Operating Systems
These systems are characterized by having time as the key parameter. These systems are often met with hard deadlines. For example, in an assembly line production, a welding machine is supposed to weld after certain intervals of time. A little too early or a little too late and there would be loss of the item being produced. This is called a hard real-time system.
In another version of RTOS, a soft real-time system, missing deadlines won’t lead to loss of the item. An example of this is a digital telephone.
Smart Card Operating System
Smart cards are basically credit card sized devices with an electronic chip. This chip has to be inserted into a terminal to get activated. Some cards hold even money that can be used for transactions later, like preloaded debit cards. Some cards become more secure with the chip, like the smart card that you insert in your digital receivers. This becomes easy to identify each user with a different smart card to give separate users separate privileges.
Other common examples of the smart cards are your sim cards.