CHAPTER 4. HTML TAGS AND ATTRIBUTES 39
4.2.2 Some Tags Stand Alone (Void)
The other kind uses a single tag and does not surround any text. These are
calledvoid tags.
Instead of marking up the existing content, void tags insert additional con-
tent, such as an image or a line break.
These are some commonly-used void tags: base, br, hr, img, input, link,
meta.
Check out this picture: 
4.2.3 Starting and Ending a Tag
Exam Question 54(p.339):What character marks the start of each piece
of HTML markup?
Required Answer:<
Exam Question 55(p.339):What character marks the end of each piece
of HTML markup?
Required Answer:>
Exam Question 56(p.339): What two characters can mark the end of
HTML markup for a void tag?
Required Answer:/>
Some authors strongly recommend using/>at the end of each void tag. I
don’t believe that any more.
Exam Question 57(p.339):When a tag is void, what does that mean?
Acceptable Answer:it cannot have a separate end tag
Exam Question 58(p.339):When do you need a space before the end of
HTML markup?
Acceptable Answer:If the markup ends in />and a non-quoted attribute
value is right before it.
The reason you need a space between a non-quoted attribute value and />
is to avoid having the / wrongly accepted as part of the attribute value.