Usually several memory cells share the same address. For example, a 4 bit "wide" RAM chip has four memory cells for each address. Often, the width of the memory and that of the microprocessor are different; for a 32-bit microprocessor, eight 4-bit RAM chips would be needed.
Occasionally, more addresses are needed than can be provided by a device. In thatthis case, external multiplexers to the device are used to activate the correct device that is being accessed. RAM is often byte-addressable, although it is also possible to make RAM that is word-addressable.<ref>{{cite book | url=https://books.google.com/books?id=QGPHAl9GE-IC&dq=size+of+a+memory+address&pg=PA321 | isbn=978-0-7637-3769-6 | title=The Essentials of Computer Organization and Architecture | date=2006 | publisher=Jones & Bartlett Learning }}</ref><ref>{{cite book | url=https://books.google.com/books?id=-vQCEAAAQBAJ | title=Foundations of Computer Technology | isbn=978-1-000-15371-2 | last1=Anderson | first1=Alexander John | date=25 October 2020 | publisher=CRC Press }}</ref>
