By default WordPress uses the native slugs (post names) that are created when the first title is set, but not changed when the title is updated.
If you would like to check your current slug, you need to enable one additional metabox in “Edit post/page” admin section using “Screen Options”. After you select the “Slug” checkbox, the metabox with slug editor should be displayed below the content editor:
How to automatically update the permalinks when the post/term title is changed?
It is pretty easy and after you enabled “Force custom slugs” mode, you need to enable also “Auto-update permalinks” option in Permalink Manager settings. After that every time you save/update the post and the post title is changed, the active custom permalink will be updated.