Dubai public transport is very convenience and comfortable .You can take Dubai metro from airport . Metro is connected to Airport and walking distance . .
There are few cards available
Nol Blue card is a personal card with secure e-purse . Ideal for frequent travellers
Nol Gold Nol Card can access to Metro Class Seats for premium charges
NOl Red Card is a paper ticket which can be loaded with 10 trips and used only one mode of transport
Nol Silver CardIf you are visitor just take Nol silver Card. I bought the card 2 years ago 2016 . Now 2018 wow the balance still there not expired :) .
You cannot use cash to pay Dubai metro , Dubai Tram , Bus and Water buses . So you must purchase Nol Card . You can get it from any Dubai Metro , some bus stations or Metro Vending machine. This card is rechargeable .
As i said Dubai public transport is convenience . Yes it is . That why i like Dubai . You can go by metro to this tourist place like Burj khalifa , Dubai Mall, Mall Emirates , and etc .
If you want go to Marina , Dubai beach , Atlantis and burj Arab . You can take Tram . Tram is bit pricey compared to Metro.
Marina and Dubai beach is walking distance from Tram .
Bus is the most cheap transport . Full of pakistani, indian , and philippines. Hard to see local Emirati in bus / tram or metro . Maybe most them rich have car .Bus also go tourist place . but i prefer go by metro more comfortable.