Centers the text on the page. Anything placed between the center tags is centered. Therefore, you can use one set to center a whole block of things on the page. Puts the lines of text into a paragraph. Does not indent.
Web browsers ignore spaces and tabs.
Bold, italicize, or blink the text. This can be used within other tags and does not require a closing tag. The standard default is size 3. Therefore, it does not require a closing of the attribute, only a closing of the tag itself. This holds true for all tags with attributes.