Adwords offers four options to determine when your adverts are shown when adding keywords to your campaign. These are as follows:
Broad Match - as the name suggests this will trigger the largest number of impressions. Your advert will be shown for similar phrases and variations in terminology. For example adding a keyword phrase such as "tennis shoes" might trigger your advert to be shown for searches for "tennis", "tennis shoes", "red tennis shoes", "tennis trainers" etc.
Phrase Match - this is more targeted than a broad match but not as restricted as an exact match - your phrase must appear with the words in the right order in the search term.
Exact Match - use the keyword editor tool or enter phrases in square brackets to indicate an exact match - e.g. [web designer london]. Using an Exact Match will mean that your ad will only be shown for search phrases that match your search phrase exactly.
Negative Match - you can add negative keywords either using the "negative keywords" tool at the bottom of each AdGroup or by adding a minus sign in front of a term (e.g. "-travel"). Negative keywords can be very useful - using Adwords reporting you can view a list of all the search terms that triggered a click through to your site. If for example you sell insurance but do not offer travel insurance adding "-travel" will exclude search phrases that include the term.
