For business wear, as the back of your shirt will always be covered by your suit, pleats and darts will only serve a functional purpose.

Pleats

The point of any type of pleat is to allow room for expansion while maintaining shape (think accordions). There are two main types of pleats.  A box pleat which is located right on top of the wearers spine and side pleats that are situated to closer to the armholes. The main consideration with pleats is to allow for mobility, especially if you like your clothing very fitted. Stylistically, side pleats looks cleaner and sleeker, but pleats with business wear is a decision where one can rightfully put function over fashion.

Darts

Darts are the opposite of pleats.  They are installed to shrink a shirt and give it a more form fitting appearance.  More commonly seen in women’s clothing to accommodate the curves of a lady we often see them in off the rack shirts that have been tailored to better fit the wearer. 

Front to back. Now you know.