For those of us old-timers on the web – we may feel weary about creating file or directory names with spaces in them. See back in the days of Netscape Navigator and the early days of Internet Explorer – spaces were treated by browsers and servers as the end of a URL. So something like http://www.somewhere.com/my directory/some page.html ends up being seen as http://www.somewhere.com/my directory/some. As such webmasters would never use spaces within their directory or file names.
These days however most browsers will automatically replace spaces in your URL with %20 – thus turning the above URL into https://www.somewhere.com/my%20directory/some%20page.html. Furthermore servers have adapted to understanding spaces, and so have search engine bots.
Google also doesn’t really care if you use spaces or not. It would prefer it if you used hyphens, plus signs, or %20 – but you won’t be penalized for using spaces if you wish to. Google does however ask that you avoid special characters within your URL since it may make it harder for Google to automatically detect your link when it’s used in a plain-text format.
So does it really matter still? On 99% of online platforms it doesn’t matter from a technical standpoint & numerous debates across numerous SEO communities have shown it doesn’t really matter from an SEO perspective. However the hardcore webmaster community will look down on you if you use spaces within your URLs.