Line of credit vs. hard money: which is better?

[Tim Ball]

I am very familiar with hard money but I am not certain exactly how lines of credit are set up.  If you are able to secure a line of credit, and you are looking to purchase buy-and-hold properties, would that be a better route than using hard money?  I know hard money is more expensive but how do credit lines work? If I bought a house on a line of credit, how long is the life of the loan?  Can I pay it off early?  Can I refi out of a line of credit purchase to a conventional mortgage on the house?  I am looking to start buying rentals and was wondering what would be the better route and why?  Let me know please.  Thank you.