2D and 3D Airflow ,.,.,.,.?

[Engineerpaii]

hi,
HOW 2D AND 3D AIRFLOW OCCURS ?
in the basic Aerodynamics we say that aerofoil and wing are identical words.but as the book progressed,the writer says that aerofoil and wing are different due to 2d and 3d airflow respectively
i browsed alot but can't realized the real concept,although i know the 3-Dimensional Concepts as i had Already done Electro Magnetic Fields, but when it comes to air ,it really troubles alot,.,.,.kindly help meee....!

 

[rb1957]

airfoil usually refers to the wing cross section, ie a 2D shape. as such it's like a wing with infinite span. An airfoil will have section properties, like Cl and Cd.

wing refers to an actual wing, with a limited span and wimg tips. the wing tips cause vortices and a significant amount of lift-induced drag. A wing will use the 2D Cl to determine the amount of lift (L = Cl*q*S); drag is a combination of Cd and Cl.