先决条件–操作系统类型
1.批处理：
批处理系统是处理大量数据的有效方法。在一段时间内收集一组交易的地方。收集，输入，处理数据，然后产生批处理结果。批处理系统的主要函数是自动保持批处理作业的执行。这是批处理系统的重要任务，即由位于主存储器低端的“批处理监视器”执行。
2.实时处理：
实时处理系统是非常快速响应的系统。这些系统用于必须在短时间内接受和处理大量事件(通常是外部事件)的环境中。实时处理需要快速处理，并且具有立即响应的特点。例如，国防应用系统(如RADAR等)
以下是批处理系统和实时处理系统之间的区别。
| SR.NO. | Batch Processing System | Real Time Processing System |
|---|---|---|
| 1 | In batch processing processor only needs to busy when work is assigned to it. | In real time processing processor needs to very responsive and active all the time. |
| 2 | Jobs with similar requirements are batched together and run through the computer as a group. | In this system, events mostly external to computer system are accepted and processed within certain deadlines. |
| 3 | Completion time is not critical in batch processing. | Time to complete the task is very critical in real-time |
| 4 | It provides most economical and simplest processing method for business applications. | Complex and costly processing requires unique hardware and software to handle complex operating system programs. |
| 5 | Normal computer specification can also work with batch processing. | Real-time processing needs high computer architecture and high hardware specification. |
| 6 | In this processing there is no time limit. | It has to handle a process within the specified time limit otherwise the system fails. |
| 7 | It is measurement oriented. | It is action or event oriented. |
| 8 | In this system sorting is performed before processing. | No sorting is required. |
| 9 | In this system data is collected for defined period of time and is processed in batches. | Supports random data input at random time. |
| 10 | Examples of batch processing are transactions of credit cards, generation of bills, processing of input and output in the operating system etc. | Examples of real-time processing are bank ATM transactions, customer services, radar system, weather forecasts, temperature measurement etc. |