More than one user can edit your website if you wish. However they will need to login using the same login details as the site owner, so they need to be someone that you can trust. For reference, it is not possible to assign different login details for different users.

When there are multiple users editing the website, you have to be careful that any changes made are not overwritten by someone else. This is especially important if more than one person is editing the same page, or making global changes such as making changes in Site Settings. Once the 'Save & Close' or 'Save & Continue' buttons have been pressed, it is not possible to revert to a previous version of a page. Having a one-person-per-page rule helps to avoid losing data.