Microsoft Edge is called Edge because:

• Microsoft's new Edge Chromium browser is now available for download on Windows and macOS. Just over a year after the software company announced its ambitions to move to Chromium, a stable version of the browser is now available for everyone to download.
• Microsoft Edge is the new browser for Windows 10, replacing Internet Explorer (IE), which first appeared with Windows 95 and remained a feature of Windows operating systems for the next two decades. Edge is a simplified, smaller browser built on Web standards and optimised for Web services.
• Microsoft Edge is a web browser created by Microsoft that comes pre-installed on all new Windows computers.
• Edge was created to be a replacement for Internet Explorer, and it is faster and more feature-rich.

Read More: What happens if I switch from Microsoft Edge to Chrome?