Uptime can be defined as the time for which a computer is operational. The opposite of uptime is downtime during which the computer remains nonoperational. Uptime is usually measured as percentile. Uptime says when a computer is working or available and is used as measure of the operating system’s stability or reliability. In this time, the machine may be left unattended and it will not crash. You will also not need to reboot the machine for administrative and maintenance purposes. Without knowing uptime, it may be hard to understand a service’s value.
So, the Service Level Agreement or SLA typically states the uptime and downtime ratio to show how long services can be expected to stay operational. When a machine has been operational for three weeks continuously, it can be referred to having a three-week uptime. When choosing dedicated hosting providers, it is imperative to inquire about their uptime guarantees.