Terms of Adwords and What They Mean

Campaign

Campaign is a set of ad groups (ads, keywords, and bids) that share a budget, location targeting, and other settings. Your AdWords account can have one or many ad campaigns running.

Ad group

A set of keywords, ads, and bids that is a key part of how your account is organized. Each ad campaign is made up of one or more ad groups.

Daily Budget

Your daily budget is the amount that you're willing to spend on a specific AdWords campaign each day.
On any single day, the AdWords system may deliver up to 20% more ads than your daily budget calls for. This helps make up for other days within the same billing period in which your daily budget is not reached.

Keywords

Words or phrases describing your product or service that you choose to help determine when and where your ad can appear.

The keywords you choose are used to show your ads to your people. Select high-quality, relevant keywords for your ad campaign to help you reach only the most interested people who are more likely to become customers you want. 

Cost-per-click (CPC) bidding

Cost-per-click (CPC) bidding means that you pay for each click on your ads. You set CPC bids to tell Google how much you're willing to pay for each click.

Impressions

How often your ad is shown. An impression is counted each time your ad is shown on a search result page or other site on the Google Network.