Hi,

Document alias is generated by default from the document name (this can be changed). The URL Path is generated by default from the Document alias or document name - according to the setting in site manager "Use name path for URL path".

Regrettably, there is no documentation - but it could be. However, the behavior is pretty easy to track down.

Document alias: changing this you can change the URL of the document without the need to change the document name (e.g. you want to have the document named Home but accessible under /index.aspx URL)

On top of that is the custom document URL path - here you can change the URL more - e.g. you want to have the home page to have the url with some structure - /homefolder/anotherfolder/index.aspx. Or, in most cases it is used vice versa - to hide the folder strucutre in the URL.

301 redirect - yes, if the system is set so: Site Manager -> Settings -> URLs and SEO -> Allow permanent (301) redirection

Best regards,
Juraj Ondrus