Ctrl + Alt 누르고 키보드 화살표 위/아래로 움직이면 멀티라인 선택이 됨거기에 키보드 입력을 하면 멀티로 적용이 됨

Install Live Server Extension in VSCode.Right-click on index.html and "Open with Live Server".Now access your page via http://127.0.0.1:5500/index.html (or similar).Fetch will work properly as the page is served over HTTP.

Open both files in VS Code.In the Explorer panel (left side), right-click the first file and select "Select for Compare".Then, right-click the second file and select "Compare with Selected".A side-by-side comparison will open showing the differences.