Browser resize vs Responsive Design Mode

[igoryen]

Hello,
Could anyone please explain the difference between resizing your browser and switching it to the Responsive Design Mode?
The reason I am asking is that it seems these 2 actions return different results on this application I am working with: resizing a page in Responsive Design Mode seems to indicate that there is a min-width="980px" set somewhere, while simply resizing the page doesn’t run into this problem.
Thanks very much.

[Jitendrayadav]

When you test web page in any tool which shows the website is responsive or not, then it counts the vertical scroll bar.
Concerning the browser for responsive testing, the browser will give 20px width difference; It is due to the browsers default scrollbar width.

[igoryen]

So can both methods be used to test responsiveness? But what is the difference between them?

[Author]

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