1.服务器：
服务器，顾名思义，基本上是由具有更高可靠性或质量部件的硬件连接到局域网、广域网和互联网的计算机或PC。它只是通过计算机网络访问、保存和传输来自其他计算机机器的所有数据和文件。
示例： Linux、NetWare、Web 服务器等。
2. 主机：
大型机，顾名思义，是一类可以处理和控制大量连接用户、大量事务并提供更可靠性能的计算机。它适用于运行可扩展软件和处理大规模并行操作。它被认为是每秒执行数百万笔交易的最佳平台。
示例： IBM zSeries、System z9、System z10、NonStop 等。
服务器和大型机的区别：
|
Server |
Mainframe |
|---|---|
| It controls and handle access to hardware, software, and other resources on network. | It controls and handle hundred and thousands of connected users simultaneously. |
| It provides centralized storage for programs, data, and information. | It provides storage for instructions, information, and huge amount of data. |
| These are small in size as compared to mainframe therefore require less floor space. | These are huge in size as compared to server therefore requires more floor space. |
| It is more cost effective as compared to mainframes. | It is more costly as compared to servers as its initial cost, cost of running, and maintenance cost is very high. |
| It provides various functionalities such as sharing data or resources among users, performing computation for client. | It provides e-commerce and mobile world more reliable, available and scalable way to perform their basic business functions. |
| They are designed to not only help business with data storage but also to improve efficiency and productivity. | These computers are designed to handle large-scale processing, data storage and other tasks. |
| It cannot handle huge volume of transactions, high reliability and different types of workloads. | It supports and handles huge volume of transactions, high reliability and support different types of workloads. |
| It is used in digital applications such as Big data, Edge, Cloud applications and IoT applications, etc. | It is used in Banking applications, high volume OLTP (Online Transaction Processing) applications, back-end systems, etc. |
| Cloud options are limitless and available in huge quantity. | Cloud options are limited in mainframes. |
| Performance of server get impacted if any components are overloaded. | Performance of mainframes does not get affected even if memory is overloaded. |