Modern web browsers like Chrome, Firefox, Safari and Edge have a suite of tools available for web developers. They are used to help create, troubleshoot and debug software built for the web.
What is the Developer Console?
Most web browsers have an interactive “developer console” that allows real-time manipulation of a web page.
This is great for web developers, because they can find bugs and fix problems quickly in the browser.
They’re a feature of your web browser, but unless you know what you’re doing we’d suggest against it.
Should I copy / paste code I found online?
Copying and Pasting any code that you find online (or were sent by someone else) is risky, because you could be unintentionally giving someone else access to your account, data or device.