Uptime is a measurement of how long your site operates without going offline. The longer your site stays up, the more traffic it can handle and the more money you can potentially make if your site is for a business. Imagine you've narrowed down where to hang your art to two places: One is open two days a week and the other is open seven days a week. You want more people to see your art so you go with the place open seven days a week. That's similar to uptime. However, uptime can be confusing. Generally when you see something is 99% effective, you think that's pretty good. But a 99% uptime means your site is down for over three days a year. The industry standard uptime is 99.9%, and anything more is best for you and your visitors. Most web-hosting services have uptime guarantees and offer some form of reimbursement if your site is down longer than the guaranteed uptime.