Depending what type of rba you purchase, the atomizer (The coil and wick components) are included. The ZAP, be it the Z-Atty Pro or Z-Atty U, already have the wick and coil installed plus additional coil wire and pre-made wicks for you to install after the initial setup wears out (replacement) a few weeks or months later. Others, such as the AGA-T2, have the Atty-Kit included, but you always have to build the coil and wick and install it yourself.
There are still other RBAs where you have to purchase the Kanthal wire (coil) and stainless steel mesh (wick) separately, but I don't know which ones.
i see. if i decide to splurge on a z-atty-pro i wont need to buy anything else to get it working since it already has everything. thanks for clarifying this for me.