"Power Edge Raid Controller". Someone else's RAID controller with a Dell label slapped on it for branding.
It is usually a bit more complex than that, although generic firmware is often available if you want to de-brand a Dell card.
Dell's servers often have an "integrated" slot which takes a different version of the PERC card (often with a model number ending in "i" for Integrated). That slot doesn't accept generic cards (the BIOS will usually complain about "unrecognized card in integrated slot" or similar). If your planned usage will use most or all of the available PCIe expansion slots, using the integrated controller may mean the difference between a workable configuration or needing to move to a larger model to get additional slots.
It is possible to save money by purchasing the controller elsewhere (like eBay), but bear in mind you no only need the controller but chassis/backplane-specific data cables, the battery or capacitor backup unit and possibly a battery cable and/or bracket as well. And of course there's no Dell warranty on an eBay purchase.
If you or your company is buying from Dell, presumably you're doing it for ease of configuration, warranty and support and not price - just get the offered PERC controller and call it a day.
One word of caution - Dell sometimes offers SATA drives as the default in some configurations. If you're going to spend the money for a PERC card, make sure you get SAS drives as well. Some configurations offer hot-swap and non-hot-swap models. You'll probably want to get the hot-swap version.