Looking for a good explanation on Craft login and if it is using persistent cookies or session cookies, etc...? I am coming from a .NET/C# authentication and session environment.  I have used {% requireLogin %} to create a secure area on the front-end of my website, but it seems that the login credential (or cookie) stays persistent after the browser is closed.  There does seem to be time factor as the next day a login is required, but the same day after a somewhat short period with the browser being closed I can relaunch the browser and I have full access to the secure areas and the system knows my user account, etc...

Looking for some direction to explain the Craft security and cookie lifespan in more detail.
You're probably looking for the userSessionDuration config setting where you can adjust the length of time an authenticated Craft session should have (or just have it session/browser based).

Other related session config settings you might be interested in:

https://craftcms.com/docs/config-settings#elevatedSessionDuration

https://craftcms.com/docs/config-settings#rememberedUserSessionDuration