Define line of flow and streamline.

(N/A) $1$. Line of Flow: $A$ line of flow is a curve whose tangent at any point is in the direction of the fluid velocity at that point. It represents the path taken by a fluid particle as it moves through space.
$2$. Streamline: $A$ streamline is a specific type of line of flow in a steady flow,where the velocity vector at every point along the line is tangent to the streamline. In steady flow,the pattern of streamlines remains constant over time,meaning fluid particles follow the same path.