We have also included some advanced tips below to supplement and expand upon the article linked above. There are multiple techniques for avoiding downtime when transferring websites, and you will want to choose the method most appropriate for you and your site. Some methods are more technical and/or require more attention than others.
What about my Database?
Your database(s) will be copied over to the new server as part of the transfer process. If your database does not change much (for example, it only changes when you add new posts or pages to your site), then there is little risk of lost information during the transfer process.
On the other hand, if you have a website where the database in constantly being updated with new information, such as forums or a site with lots of user generated content, you will want to take special care to make sure no information is lost in the transfer. There are a couple ways of doing this.