Solo Missions

UnKnown

In the game when you start the solo missions it introduce you to the lines on the ground representing what you completing depending if you completed it, explore it
But the question is what do they actually mean?

Shadowbound

Not sure I understand the "what do they actually mean" portion but;

If its a thick line don't go that way, its been done,no other routes available.

If its any other dashed style line go that way and you'll be moving toward an unexplored path.

Hope that answered your question. Have fun!