Operating systems have come a long way from the actual first computer generation and they continue progressing with time. In this section, we will talk about several essential categories of operating systems that are most utilized.

Batch operating system

The operators of a batch operating system (OS) do not relate with the computer completely. For each user organizes his job on an disconnected machine such as punch cards and proposes it to the computer operative. To accelerate processing, works with like desires are batched simultaneously and run as a band. The computer programmer’s put their packages with the operative and the operative then sort out the packages with alike constraints into batches.

The challenges with Batch OSs are as given −

• Absence of communication among the operator and the job.
• CPU (Central processing Unit) is frequently idle as the tempo of the routine I/O (Input output) devices is sluggish than the CPU (Central processing Unit).
• Complicated to offer the preferred precedence.

Time-sharing operating systems

Time-sharing may be a technique that permits many of us, located at various terminals, to use a specific computing system at an equivalent time. Time-sharing or multitasking may be a logical extension of multiprogramming. Processor's time which is shared with numerous operators simultaneously is termed as time-sharing.

The major distinction among the Multi programmed Batch Operating systems and Time-Sharing Operating Systems is that within the event of Multi programmed batch operating systems, the objective is to extend processor usage, whereas, in Time-Sharing Operating Systems, the objective is to decrease feedback time.

Various jobs are performed by the CPU (Central Processing Unit) by changing among them, but the changes happen so commonly. Therefore, the operator can take an instant answer. as an example, in trade processing, the processor run and executes every individual operator software during a compact volley or quantum of calculation. Such is, if the n operators are working, then every individual user can get a time quantum. while the operator submits the request, the reply time is typically in some seconds at the most utmost.

The OS utilizes CPU(Central Processing Unit) scheduling and multiprogramming to supply per user a moment piece of the time. Computer devices that were produced originally as batch systems got transformed into time-sharing systems.

 The advantages of Timesharing operating systems are as given−

• Offers the convenience of immediate acknowledgement.
• Malingers replication of programs.
• Diminishes CPU (Central processing unit) idle period.
• Limitations of Time-sharing OS are as given −
• The difficulty of authenticity.
• Issue of security and sincerity of user-defined programs and knowledge.
• The dilemma of knowledge transmission.

Distributed OS

Distributed devices use numerous central processors to help numerous real-time processes and various operators. processing tasks are allocated amongst the processors respectively.

The processors interact with one another by numerous transmission channels(like rapid buses or telephone channels). These are indicated as loosely linked systems or shared systems. Processors during a distributed system may differ in size and capacity. These processors are related to sites, nodes, machines, and lots of more.

The benefits of distributed systems are as follows −

• With a resource sharing facility, a user at one site could also be ready to use the resources available at another.
• Speed up the exchange of knowledge with each other via electronic message.
• If one site fails during a distributed system, the remaining sites can potentially continue operating.
• Better service to the Operators.
• Decrease of the load on the host computer.
• Reduction of delays in processing.

Network OS

A Network OS works on a server and offers the server the potential to control information, operator, organizations, confidentiality, administration, and several networking purposes. 

The primary purpose of the network OS is to authorize shared data and printer entry with numerous devices while a network, LAN, a personal network or different networks.

Some of the  well known Network os's are Windows server , UNIX, Linux, Mac OS X, Novell NetWare, and BSD these are the most important and trusted Network os till now.

The benefits of network operating systems are as given−

• Centralized servers are extremely stable.
• Security is server controlled.
• Upgrades to new technologies and hardware are often easily integrated into the system.
• Remote access to servers is feasible from different locations and kinds of systems.
• The limitations of network operating systems are as given−
• Too expensive for and working as a server.
• Dependency on a prime location for many operations.
• Normal maintenance and updates are needed.

Real-Time OS 

A real-time system is generally described as an information processing system via which the period needed to prepare and react inputs is so little that it checks the situation. The time demanded by the system to respond to input, and show required updated data is called the reaction time. So, when this method, the reaction time is extremely less as compared to online processing.

Real-time systems are employed when there are tough conditions on the function of a processor, or the flow of information and real-time systems are usually used as an backup system during a dedicated application. A real-time OS must get well-defined, fixed time restraints, else, the system will fail or won’t work. for instance, Scientific experiments, medical imaging systems, industrial control systems, weapon systems, robots, traffic control systems, etc.

Real-time operating systems are of two types.

• Hard real-time systems - Hard real-time systems guarantee that complicated works will be completed on time. In hard real-time systems, auxiliary storage is restricted or missing and therefore the data is stored in ROM. In these systems, virtual storage is never found.
• Soft real-time OS - Soft real-time systems are less definitive. A critical real-time job gets precedence over different tasks and maintains the advantage until it ends. Soft real-time systems have defined resources than active real-time systems.