The difference in the two is this:
Line your hired with a living wage to do the comic exclusively for them (thou you still hold the IP, they hold the publishing rights). Which is cool for getting a good income. But due the inexclusiveness I believe you won't be able to print it for comic con circuits or make merch since that takes money away from Line. Do your sole job is comic creation, oh but according to THIER rules of formatting and content (they have editors I believe)
Taps and anywhere else, you still owe it entirely, IP & publishing rights. This is more of a freelancer options. Most make money off support, book sales, merch, comic con circuits and ad rev.