Difference in Issue offered for sale by SoccerJerseyInSG

Nike
Fan issue are those jersey that are commonly found in retail store outside. They are the most basic type of jersey available.
Player issue are the identical article (material, cut and fitting) which most soccer player prefers. As they have a better body fit and higher quality material which keeps them cooler.

Its material are much smoother and much more comfortable and lighter too.
It has a T-bar accross its shoulder just like jersey worn by players during matches.
Its club"s logo and NIKE logo its made of digital printing NOT embroidery.
It has air-holes by the side to enhance ventilation.
Pro combat will be the same as what the players are wearing on the field. They have the features of player issue but are more tight fit. They are also known as compression jersey.


Adidas
For adidas, we have the climacool which is also similar to the fan issue for Nike. They are those basic type of jersey available that are commonly found in retail store outside.Techfit will be similar to the pro-combat for Nike whereby there are the same as what the players are wearing on field. However for techfit, there are not much significant features and one of it will be the strip rubber strip that are found on the bottom of the shirt. Techfits like what its name says are meant to be more tight fitting and it will fit to the shape of your body. It also has high ventilation which will keep you cool and comfortable.  

***NOTE***
For Nike, most clubs will have the player issue but not all will have the Pro-combat version.Likewise for Adidas, only selected clubs will have the Techfit issue.