Amazon PPC glossary
Exact match
Exact match is the tightest option. Your ad shows only for that exact search, or a very close variation of it. It gives you the most control and usually the most predictable results.
Example
Your keyword is “yoga mat.” Your ad shows when a shopper searches “yoga mat” or a very close variation, but not for “thick yoga mat for travel.”
Where it matters most: Book 1, The Amazon PPC Clarity Guide, in the chapter “Campaign Architecture.”
Go deeper
The glossary gives you the one-line answer. The Amazon PPC Clarity Guide explains why it matters and what to do about it.