Keywords in SEO play a pivotal role in enhancing your visibility online. So what exactly is an keyword in SEO? Let's break it down.

In online advertising, a keyword is a particular term or expression that people type into search engines when they are trying to find a certain service, product or information. SEO heavily is centered around the use of these keywords to position websites.

The essence behind SEO keywords lies in their ability to relate what users are searching for to the content that you’re offering on your website. Strategically using these keywords will help attract the right audience and increase the likelihood of conversions.

Having established the concept of an SEO keyword, let's look at methods for efficiently using keywords. Improving the use of keywords demands a balance. You'd want to include relevant keywords to appeal to search algorithms but not overly saturate your content with them.

One way is to place the keyword in your content’s headline. This not only helps in optimization, but also makes your content more likely to be relevant to the searcher's query. Next, consider using keywords in the meta description and headings of your website, as these website are places where search engines tend to look.

It's also essential to choose keywords that align with your target audience. This signifies understanding their lingo, their search behaviors and their requirements.

In summary, a well-chosen SEO keyword can act as a bridge between what a person is looking for and the service or information you provide. It's a critical tool for success in the aggressive world of digital marketing. However, as with all tools, using it correctly is the key to unlocking its full potential.