A search term refers to the same word or a set of words that are entered by a customer when he searches for any particular information. This report enables the advertisers to find out the actual search query the customer went through and ultimately that forced him to click. The searched word does not necessarily mean the exact question, but it could be related to that word.
By doing this, you can identify new search items that have a high potential, to add them to your list of keywords. This also gives you a good idea of certain terms that are not important for your business, so you can use them as negative keywords.