Answer:
The four types of maintenance in IT are given as:
Preventive maintenance: It is the important part to facilitates the management system and it should be designed carefully o prevent them from failure. the main aim of preventive maintenance is to successfully establish the design to improve the system performance.
Corrective maintenance: It basically refers to the changes made to repair the defects in the implementation and designing of the system. It is usually performed after the failure occur in the equipment. It also increased overall productivity of the system.
Perfective maintenance: It basically improve the performance of the system, efficiency and maintainability. This type of maintenance are initiated by the IT department.
Adaptive maintenance: It involves the implementation changes in the system to increase its functionality. It basically improve its efficiency and increase its capability. It is less urgent than corrective maintenance.