AdWords is Google’s advertising system that allows users to bid to the highest spot on their Search Engine Ranking Page (SERP). The better your ad relevance and higher your bid, the more likely you are to rank well and receive more clicks because of it.
The service of Google AdWords itself is pretty popular, holding 30% of the global net ad revenue in 2015 (SearchEngineLand), and with good reason. Depending on your market and how active your competitors are, it can be a great way to get in front of your audience as they search as long as the cost of acquisition makes sense for your business.
Campaigns are your highest bucket, followed by Ad Groups, which is where your ads live. Like everything in inbound marketing, your Ads are fueled by keywords.
Campaigns are great for organizing at a high level and can be targeted to specific locations. This is also where you will set the type of search network (group of search-related websites where your ad can appear) that you would like to use.