Uniform Resource Locators (URLs) function as the address of unique resources on the internet. Entering a website URL into our browser retrieves the HTML/CSS files required to construct the page we’re visiting, and making API calls against an endpoint URL allows us to remotely access and/or modify important data — the list goes on. URLs effectively facilitate the interconnectivity we take for granted on the internet today.
When we capture URL string inputs in our web applications, it’s critical that we validate those inputs to ensure the URLs are useful. Retrieving and storing any form of address data (whether that's a URL address, an IP address, or even a physical street address) without immediately validating its utility is a waste of time; it’ll leave us empty-handed when we attempt to access important resources in the future.