触摸屏是PLC人机界面的一种，人通过触摸屏幕上的按钮等就可以调整参数或监视参数。但人机界面不一定全部是触摸屏的，有的是在操作面板上安装了若干个按钮，人通过按钮来监控PLC运行。这种界面的屏幕只是用来观察参数，没有触摸操作功能。
Touch screen is a kind of human-computer interface of PLC. People can adjust parameters or monitor parameters by touching buttons on the screen. However, the human-computer interface is not necessarily touch-screen, some of which are installed with several buttons on the operation panel. People monitor the PLC operation through the buttons. The screen of this interface is only used to observe parameters, without touch operation function.
触摸屏是人机界面，但触摸屏幕只是人机界面中的一种。人机界面还包括非触摸屏的，还有上位机，文本显示器等。连接PLC总是人机界面的一个功能，能实现人机交互的操作界面就是人机界面。
Touch screen is a human-computer interface, but touch screen is only one kind of human-computer interface. The human-computer interface also includes non touch screen, upper computer, text display, etc. Connecting PLC is always a function of human-computer interface. The operation interface that can realize human-computer interaction is human-computer interface.
严格意义上来说，“触摸屏”是具有触摸操作功能人机界面的一种输入设备而已，在工厂里具有触摸输入功能的人机界面被习惯称为“触摸屏”。
Strictly speaking, "touch screen" is a kind of input device with touch operation function human-machine interface, which is used to be called "touch screen" in the factory.