as an example 

in a bus station if u are sitting on a bench u and a woman so she is sitting beside you and if there is a man standing somehow distant from you so he is near u

hope u got it :)

I'm study english, but what I learned was it: Near is anything or anyone that is around of you or something (ex: the bakery is near of us, it is in the same street that us) . Beside is anything or anyone that is on your side (ex: That woman is beside of me, she is touch in my arm).

I speak portugues, then can it have some mistakes.

Near means not far away in distance or space,but beside...is more like 'next to', Ahmed's example explains about that