The window.open will open url in new browser Tab
The window.location.href will open url in current Tab (instead you can use location)
Here is example fiddle (in SO snippets window.open doesn't work)
var url = 'https://example.com';_x000D_
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function go1() { window.open(url) }_x000D_
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function go2() { window.location.href = url }_x000D_
_x000D_
function go3() { location = url }<div>Go by:</div>_x000D_
<button onclick="go1()">window.open</button>_x000D_
<button onclick="go2()">window.location.href</button>_x000D_
<button onclick="go3()">location</button>