A website isn't finished once it's online. These items always come up. The only question is whether they're included or extra.
DomainYour address on the internet, for example your-business.com. Has to be renewed every year.
HostingThe server the site lives on. Without it, nobody can reach it.
SSL certificateThe padlock in the address bar. Without it, browsers warn your visitors.
Updates and backupsTech gets old. If you do nothing, sooner or later you have a security hole or a broken site.
Legal pagesLegal notice and privacy policy must be correct and updated when laws change.
Small changesNew opening hours, new prices, a new photo. Sounds small, but costs time or money.