hardware - 8-bit per cell memory?

I'm a software development student, who want to improve its hardware knowledge.

I'm reading Structured Computer Organization by Tanenbaum. In the chapter 2, the author says the following:

"[...] In recent years, nearly all computer manufacturers have standardized on an 8-bit cell [...]".

I thought this was correct, but searching over internet, I found there is no memories with 8-bit per cell!

So, my question is: Is it an error of the author or I misunderstood what he tried to explain? If so, what is, "usually", the number of bits per cell and how could I see the bits per cell of my memory?

Answer

There seems to be some confusion between memory organization (which is most often integer multiples of 8 bits wide) and bits per memory cell.

Storing more than one bit per cell can be achieved by storing an analog voltage that can be differentiated into \$2^n\$ different levels for \$n\$ bits. MLC flash can have 2 or 3 bits per cell, requiring 4 or 8 levels. It becomes progressively more difficult and thus more prone to errors and bad yields as the number of bits increases.