Many home printers use four colored inks to produce printouts.
Some of these inkjet printers use two ink cartridges only, one of which is a tri-color model.
The Epson XP-630 is an exception.

It is powered by five colored inks, each of which is housed in an individual cartridge.
Features and Highlights
The Epson XP-630 has a control panel that can be tilted upward.
It has a 2.7-inch color LCD along with touch sensitive buttons to operate printer without using a PC.

It also has a USB port, memory card slot, and Wi-Fi functionality.
Its duplexer enables the machine to print double-sided pages automatically.
To reduce the cost, you might use the XL cartridges which provides more ink.

Those components are ink pads.
They arent vital components but important enough to stop the printer from printing when they become nonfunctional.
The first one is to remove a screw and the other one is to pry the holder off.
You may also need Epson XP-630 Resetter to complete the entire process.
This utility is needed to reset the counter of the pads.