What Are URLs and Slugs?

The address that takes you to a page

In Lesson 11, we helped ClearFlow Plumbing, our fictional plumbing business in Austin, Texas, write a clearer SEO title and meta description for its water heater repair page. Those words help explain what the page is about before someone opens it.

Now imagine our homeowner finds the page useful and sends it to a neighbor who also needs water heater help. They don't have to explain where to click on ClearFlow's website. They can simply share the page's address:

https://clearflow.example/water-heater-repair

The neighbor opens that address and arrives at the same page. You probably use website addresses like this every day. In SEO, there's a name for them: URLs.

A URL is an address on the internet. In this lesson, it points to a webpage. Just as an address helps someone find a place, a URL tells a browser which online page to open. Every webpage needs an address people and search engines can use to reach it.

You may have heard the word slug too. Let's look at where that fits.

One address, two useful parts

Look again at ClearFlow's address. The website name, clearflow.example, is its domain name. Think of that as the name of the website.

The final part, water-heater-repair, is the page's slug. A slug is a short piece of the web address used to identify a particular page. ClearFlow could have other pages with their own slugs, such as drain-cleaning or contact.

The https:// at the beginning tells the browser to use a secure connection to the website. You don't need to change that for this exercise. The important part today is understanding the site address and the page address.

Some URLs have more than one section after the domain, such as clearflow.example/articles/water-heater-noise. In that address, articles groups the pages, while water-heater-noise is the final slug. The complete section after the domain is often called the path. It doesn't necessarily mean there's a physical folder with that name.

Why clear addresses are worth using

Suppose ClearFlow is about to publish a new drain cleaning page. Its website editor suggests the address clearflow.example/page-8472. That address might work perfectly well. But if a customer sees or shares it, the numbers don't explain what the page is about.

ClearFlow could instead choose clearflow.example/drain-cleaning. The address is still short, but now it gives someone a clue about the page before they even open it. It also gives search engines another small piece of information about the page's subject.

That doesn't mean the right slug guarantees a ranking. Google considers far more than the words in a URL. But clear addresses make a website easier to understand, share and manage. They are a useful part of on-page SEO, not a trick for getting to the top of Google.

If the address has several words, a hyphen is an easy way to separate them. That's why we write water-heater-repair instead of waterheaterrepair. Google also recommends hyphens when separating words in URL paths.

There's no need to force every possible keyword into the slug. An address such as /best-cheapest-water-heater-repair-austin-24-hours is long, difficult to read, and makes claims we haven't established for ClearFlow. /water-heater-repair already tells the reader what the page covers.

But should you change an address that's already live?

This is where ClearFlow's owner needs to be careful. Its existing water heater repair page has been available at clearflow.example/water-heater-repair. Customers may have saved it. Other pages may link to it. And Google may already know that address.

One day, the owner wonders whether adding the word austin would make the URL better for SEO. They think about changing it to clearflow.example/water-heater-repair-austin, even though the page still offers the same service.

I wouldn't rush to change it. The current address is already clear. Changing an established page's URL just to add another keyword isn't a reliable way to improve rankings, and it can create extra work.

Why? If someone clicks an old link after the change, it might no longer lead to the page. They could see a “page not found” message instead.

When a change really is necessary, the website owner should usually arrange a redirect from the old address to its relevant new address. A redirect is a forwarding instruction: someone visits the old address, and the website sends them to the new one. For a page that's moved permanently, a 301 redirect is a common way to signal that move to browsers and search engines.

It's also wise to update links on the website so they point directly to the new address. A redirect helps, but it doesn't promise that rankings will stay the same or that Google will update everything immediately.

Why understanding URLs helps with SEO

Remember the bigger story we've been building. First, you learned how people search and find businesses. Then you learned why a website needs pages that answer different questions. Next, you learned to write clear titles and descriptions for those pages.

A URL is the address that connects someone to a particular page. A clear slug helps people recognize what they're opening. Keeping established URLs stable also helps protect the links and paths people already use to reach a business.

When you work on a website, you now know to ask two different questions. If you're creating a new page: is its address clear and sensible? If you're changing an existing page: is a new address actually necessary, and what will happen to the old one?

That distinction can save you from making a change that looks like an SEO improvement but makes the website harder to use.