We found the shop
http://my-corner-shop.com
We tracked down the right department
/dairy
We specified the option we wanted
?product=milk
And finally added our filters.
&size=1&type=semiskimmed
It may not seem like a big deal. But now you know your way around the shop to fetch a single item, you could use the same framework for filling your trolley with a week's worth of groceries.
Now we've covered the theory with a simple analogy, why not have a look at some real-life examples of APIs you can play with. Click on each link, or copy and paste it into your browser address bar, and see what you get back. If that works, try changing the query terms and filters and see what happens.
Pokemon evolution
http://pokeapi.co/api/v2/evolution-chain/7/
Open API for air quality data
https://api.openaq.org/v1/cities?country=GB
(You can also see this API in use in this simple demo).
If you'd like to try working with an API using code rather than your browser, take a look at our Jupyter notebook.