What are the different types of software maintenance?

What will be an ideal response?

After an information system is installed, it is essentially in the maintenance phase of the SDLC, in which an information system is systematically repaired and/or improved. The types of maintenance are the following:
Corrective maintenance: Making changes to an information system to repair flaws in the design, coding, or implementation
Adaptive maintenance: Making changes to an information system to evolve its functionality, to accommodate changing business needs, or to migrate it to a different operating environment.
Perfective maintenance: Making enhancements to improve processing performance or interface usability, or adding desired but not necessarily required system features.
Preventive maintenance: Making changes to a system to reduce the chance of future system failure.