You will often see this in stores where it is assumed that users will be logged in at all times, but this is an example of how to set it up if you want to display a "Welcome Mr./Ms. XX" message in the header etc. to users who log in to Shopify.
Example of setting to display "Welcome Mr./Ms. XX" to logged-in users with the theme "Dawn"
[How to set it up] Add code to header.liquid and header-drawer.liquid
