The golf shirts on the market today have a larger chest, larger armholes, longer sleeves just up to the elbow and an extended shirt. The oversized functions provide freedom of movement during the golf swing.
The climate-cold material is made from 100% polyester that keeps you cool on those hot and humid days on the left. Due to the moisture-regulating technology, this material removes the perspiration away from your skin to keep you dry. When your skin is dry, you naturally feel cooler. The antibacterial finish helps eliminate body odor. If you have a tendency to perspire a lot, I would strongly recommend this type of material. Stay away from the 100% cotton material for your golf shirts, because when they become damp through perspiration or rain, they tend to limit your swing.
For more comfort some manufacturers such as Adidas and Izod add their size labels to the neck for less comfort. Everyone has had a golf shirt that has been smeared by the label in the wrong way. Cutting off does not help, it only makes things worse. Then you try to record it, it works for a while until the tape falls away and then you are back in the same situation. With the new label with fewer labels you never have this problem.
The new materials that the manufacturers are using now will wax their shape and comfort for many laundry products. The UV rays from the sun will not fade them as much as the 100% heavy cotton; These shirts tend to fade around the collar and shoulder areas from just outside in the sun. This is especially true for the dark colors.
The original polo shirts with classic fit are slightly smaller in the chest and sleeves. The sleeves extend halfway down on the biceps and the armholes are smaller. These features may limit your golf swing a little if you want to wear it during golf. Stay with the golf shirt for extra comfort.
There are two other styles of polo shirts to choose from. The tailored polo is smaller in the chest, has shorter sleeves and a shorter shirt tail. The slim fit polo has the narrowest chest of the two and is not made to put in your pants. These two styles will be well worn under a sport jacket, but are not recommended to wear during a round of golf.
Both golf shirts and polo shirts are designed to keep you cool and comfortable on the left or on a backyard BBQ.
I have listed some of the differences, so hopefully you will have more information at your disposal to make your next purchase.