What computer component gets data into the shaded area A?

Without a visual reference to "the shaded area A," I can only provide a general answer. Typically, the component that gets data into a specific area of a computer, such as the CPU or memory, is often the input device, like a keyboard or mouse, or a storage device, like a hard drive or SSD when referring to data transfer. If "shaded area A" refers to a particular part of a system, please clarify for a more precise answer.