System maintenance is a catchall term used to describe various forms of computer or server maintenance required to keep a computer system running properly. It can describe network maintenance, which could mean that servers are being physically repaired, replaced, or moved. Network maintenance can also mean that the software for a server is being updated, changed, or repaired. This sort of maintenance is typically performed on a regular or semi-regular schedule, often during non-peak usage hours, and keeps servers running smoothly.
Information technology (IT) professionals often use system maintenance to describe any sort of repairs being performed on a computer or multiple computers within a network. IT maintenance can often take hours to complete, and professionals usually describe the work in general terms to avoid the timely explanations required for more specific language. When websites are inaccessible due to attacks from hackers, server problems, or for updating and repair, the administrators of the website will often display an image apologizing for the maintenance and website downtime. This allows users to understand that the website cannot be used and that the administrators are aware of the issue.
Preventative maintenance is often performed by IT professionals, usually because a potential problem or security threat has been recognized with a computer or server, and the system administrators are working to deal with the issue before it becomes a true problem. This sort of maintenance is often seen as unnecessary or inconvenient by users who find work interrupted by the sudden need to fix an issue that has not yet affected the user. Preventative maintenance keeps users from encountering far more serious problems and therefore is essential to continued system reliability.
Due to the perceived inconvenience of preventative maintenance, many IT professionals prefer to rely on scheduled maintenance to perform the required system maintenance in a time frame that disrupts other users as little as possible. Scheduled maintenance is ideal for actions like emptying temporary files, running defragmentation programs on hard discs, and clearing out server caches. IT professionals may not always be able to wait until scheduled maintenance to address particularly dire problems with a computer or server. When possible, however, the administrators will often allow minor issues to persist and simply be worked around until the scheduled maintenance can be completed, rather than interrupt the users that rely on the system.