Wireless router or Device

Hello

my friend is using TP LINK wireless device ... with aztech router,,, And workiing fine with laptop,, range is quite good as well

now i wana ask should i buy TP LINK device for me

or i should buy any wifi Router..

i think TP link device costs about 2800 rs aand i dont know about Wireless router

what r main differences... price deference,, and any range issue

Can anybody tellme please