Google has recently introduced “broad match modifier”, a new AdWords targeting feature that lets you create keywords that triggers your ads to appear more than phrase match and have more control than broad match.

Before going deeper into the recently introduced “broad match modifier” let’s quickly recap the other popular keyword match option in Google adwords.

Broad Match

This is the default keyword match option. Choosing broad match option will provide maximum impressions to your ads. If you ad group contains a keyword domain registration, your ads will appear when a user’s search query contains any of the these keywords:
Domain name, domain name registration, buy domain name, register domain, name registration.

Your ads could also show for singular/plural forms, synonyms, and other relevant variations.

Phrase Match

Phrase match is more targeted than broad match, but more flexible than exact match.

If your keywords are in double quotes “domain registration” your ad would be eligible to appear when a user searches on the phrase domain registration with the words in that order. It can also appear for searches that contain other terms as long as it includes the exact phrase you’ve specified.

Domain registration, domain registration Company, domain registration service providers

Your ads will not appear on searches for:
Registration domain name, domains registration, domain name

Exact Match

If you place your ads in brackets [domain registration], your ad would be eligible to appear when a user searches for the specific phrase domain registration, in this order, and without any other terms in the query.
When using this keyword match option, your ads will appear on [domain registration]
Ads won’t show on searches for: domain name registration, domain registration companies, domain names

Negative Match

If your keyword is ‘domain registration’ and you add the negative keyword ‘FAQs,’ your ad will not appear for any searches that contain the word ‘FAQs’

Ads won’t show on searches for:
Domain registration FAQs
It’s a good idea to use negative keyword option, especially when your adgroups contains a lot of broad-matched keywords.

The latest +broad + match +modifier Option

This option is currently available for U.K and Canada advertisers and is in beta phase. To implement broad match modifier just add + before each word. If your keyword is domain registration and you want to use broad match modifier option use +domain +registration.

Each word proceeded by a + has to appear in your potential customer’s search exactly or as a close variant. Close variants include misspellings, singular/plural forms, abbreviations and acronyms, and stemming (like “floor” and “flooring”). Synonyms (like “quick” and “fast”) and related searches (like “flowers” and “tulips”) aren’t considered close variants.

To better understand this I am copy pasting the graphical representation, picking as it is from http://adwords.blogspot.com/2010/07/new-keyword-targeting-feature-rolling.html