A server is a device or computer program the provides services to other computer programs or devices (called "clients"). A server cannot be directly accessed by a human, but a computer can.
A table tag is needed to define an HTML table. There must also be one or more tr, th, and td elements. The tr tag defines a row in the table. The th tag defines a table header, and the td tag defines a table cell.
The iFrame tag allows the user to embed a seperate document (in a rectangle frame) into their own website.
The a tag defines a hyperlink that the user can click on a be redirected to another website.
The tr tag defines a table row.