Problems with PLC and relay

Most of what the landlord said is right. "The relay in PLC control is replaced by PLC. There is no relay in this control method." This sentence is correct. Generally speaking, PLC control replaces the intermediate relay in relay control, and there is no way to replace the relay that directly controls components. The relay still needs to be used. In addition, PLC is not completely used to replace relays. PLC itself has many functions, such as analog function, data processing function and communication function.