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A Quick Search Engine Marketing Glossary of Key SEM Terms

June 25th, 2024 | 4 min. read

By Kim Kovelle

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Hands on a laptop keyboard, searching Google for information

Search engine marketing, or SEM, can boost website traffic, target ideal audiences and drive conversions. However, as competition on Google grows, it takes more effort to stand out.

If you feel stumped on where to start, this search engine marketing glossary can help. At Zoe Marketing & Communications, we help businesses like yours set up successful SEM campaigns. And, as Zoe’s content manager, I’ve written extensively on how SEM works.

Here, you’ll find 21 simplified essential terms to help you easily navigate the SEM landscape. Expect straightforward explanations and a few graphics to bring things to life.

You’ll walk away with a clear sense of how SEM works. And, beyond clearing up some of the cobwebs, you’ll feel better prepared to start rolling out or refining your own SEM.


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Learn how digital ads can help your business, including the tools, techniques and strategies to create successful campaigns.

Before we begin: What is search engine marketing?

SEM is the strategy of using paid ads on search engines like Google to boost visibility, traffic and conversions. It involves bidding on keywords so your ads appear when users search for related products or services. Most often, they’re either: 

  • Text-based, which show up in search results with a “Sponsored” label
  • Display style, or image-based, which show up on other websites or apps

The most common platform for SEM is Google Ads. SEM is also commonly called PPC, short for pay-per-click, which is how you’re charged.

Search engine marketing (SEM) glossary of 21 terms

Let’s take a closer look at some key terms that commonly appear in search engine marketing, listed alphabetically.

A/B Testing

Comparing two versions of an ad or landing page (i.e., the place the ad takes people to) to determine which performs better, optimizing for higher conversions. Google Ads tracks this with its “Experiments” feature.

Ad extensions

Extra information shown with text ads, beyond the basic headline, description and URL. Examples include your phone number, location address, links to specific pages or callouts (e.g., “Free shipping”). These tidbits make your ads more helpful, potentially boosting your clicks.

SEM Glossary - Ad Extensions

Ad groups

Collections of related ads and keywords within a campaign that share a common theme. Groups let you organize and target your ads more specifically, making them easier to manage.

Ad rank

A score determining your ads’ position in search results. Rank is influenced by:

  • The dollar amount you bid on a keyword
  • Your quality score (more on that below)
  • The expected impact of your ad extensions (see above)

The higher your rank, the higher you’ll appear in the search results.

Bid strategy

The approach to setting bids for ads, aiming to maximize desired outcomes like clicks, impressions or conversions. There are 12 strategy options. A few common ones include:

  • Manual CPC: You set the maximum cost-per-click for your ads.
  • Enhanced CPC: Google adjusts your manual bids to get more conversions while trying to keep your cost-per-conversion the same.
  • Target CPA: You set a target cost-per-acquisition, and Google adjusts your bids to get as many conversions as possible at or below that cost.

Click-through rate (CTR)

The ratio of people who click on an ad to the number of total people who view it. CTRs vary by industry, but the average CTR is around 3.94%. Higher CTRs are good, but it’s important to balance them with a strong conversion rate (next on the list).

Conversion rate (CR)

The percentage of people who take a desired action after clicking an ad, such as making a purchase or filling out a form. CR shows how effective your campaign is overall. The average conversion rate is 3.76%.

SEM Glossary - Conversion rate

Cost per click (CPC)

How much you pay each time a person clicks your ad. This is a critical metric for managing your spending. On average, CPCs across industries are $1.27.

Display network

A group of websites and apps where your display (designed) ads can appear for people interested in your keywords. This expands your reach beyond search results.

SEM Glossary - Display ad


Targeting ads to people based on their geographic location. Helpful for local results, it lets you pick a DMA (designated market area), ZIP code, city, state, a radius around a locale and more.


These words trigger ads when they’re Googled. They’re the actual phrases you’re bidding on. Google Ads offers you ideal suggestions with its Keyword Planner.

Landing page

The web page people land on after clicking your ad. Good landing pages are designed to convert people quickly with direct information and a clear call to action.

Negative keywords

You can also tell Google which search terms you don’t want to appear for. Setting these up prevents irrelevant clicks and wasted funds.

Pay per click (PPC)

The primary payment model for SEM. You pay each time a user clicks on your ad. PPC is influenced by your bid amount, ad relevance and competition for your keywords.

Quality score

Google’s rating scale, from 1-10, of the quality and relevance of ads, keywords and landing pages. A score of 5-6 is average; higher scores can lead to lower costs and better ad positions.

SEM Glossary - Quality score


Delivering ads to users who have previously visited your website, encouraging them to return and complete a desired action. You do this with a tracking pixel (more on that below).

Return on ad spend (ROAS)

A measurement of how much revenue you generated compared to how much you spent on ads. A good general ROAS is a 4:1 ratio, meaning $4 in revenue for every $1 spent on ads.

Search network

A group of search engines where text ads appear to reach the best possible prospects. The most popular, Google Ads, focuses on Google Search and partner sites/apps.

Target audience

The specific group of people you want your ads to reach. You can define this by demographics like age and gender, interests or behaviors such as buying habits and websites they’ve visited.

Text ads

Simple, text-based ads displayed in search results. They include a headline, description and URL. You can also add ad extensions like location or callouts.

SEM Glossary - Text ad basic

Tracking pixel

A small piece of code that Google Ads generates for your website. It tracks user behavior and conversions, helping you retarget ads to people who left without taking the desired action.

Next steps for effective search engine marketing or SEM

If you want people to find you on Google, search engine marketing is part of a healthy marketing strategy. This handy SEM glossary can help you get your bearings as you dive in.

You’ll likely also find running effective campaigns is time consuming. If you could use support, talk to us. Zoe Marketing & Communications has 15+ years of digital marketing experience for small- to mid-sized businesses. Meanwhile, shore up your SEM campaigns with this insight:


Download Your Digital Ads Guide

Learn how digital ads can help your business, including the tools, techniques and strategies to create successful campaigns.

Kim Kovelle

As Zoe Marketing & Communications’ content manager, Kim Kovelle brings nearly 20 years of writing and editing experience in metro Detroit. She has strong roots in community journalism and a knack for making complicated topics make more sense.