Remember, computers only 'know' two values: 1 or 0 (zero), something or nothing, yes or no, true or false, etc. There are no "ifs, ands or buts." Not at the lowest level, anyway.
So, the minimum 'memory' is one bit. And it can be a 1 or a 0. Pretty simple, but not extremely useful...
Let's put two bits together on a chip. OK, now we can actually count to three!
Now we're moving! at a snails pace!
How 'bout we double those bits and have four of them! Now we're really talkin' We can now count all the way to...
0 0 0 1 = 1
0 0 1 0 = 2
0 0 1 1 = 3 (just like above with two bits)
0 1 0 0 = 4
0 1 0 1 = 5
0 1 1 0 = 6
0 1 1 1 = 7
1 0 0 0 = 8 Whoa Nelly! There's no stoppin' us now!!!
1 0 0 1 = 9
1 0 1 0 = 10* Good grief! We only have four 'fingers' and we've already reached TEN!
1 0 1 1 = 11*
1 1 0 0 = 12*
1 1 0 1 = 13*
1 1 1 0 = 14* !!!!!
1 1 1 1 = 15* And we didn't even use our feet!
Fifteen values with just four bits! But wait! There are actually sixteen values! Don't forget: 0 0 0 0 = 0
Now, if four bits are such fun, what would happen if we could double them again?! And what about 16 bits, or 32 and why not just go for broke and have SIXTY-FOUR bits!!!
You see, the 'trick' is to have each bit have a value that's twice the value of its neighbor just below it. We humans didn't think of that until recently...we just have each 'digit' equal to the same value; one! But this simple 'binary' system is really extremely valuable and efficient! Care to guess what the 'value' of the next bit we add to the four bits we had above (hint: 16) and what about the eighth added bit? Maybe...128? And guess what number 1 1 1 1 1 1 1 1 represents...with just four 'fingers!'
Of course, humans still wanted to think in round numbers. So when we got to 1024 (10 bits/fingers), some one decided it would be 'close enough' to call it a kilo-bit/byte. And this, dear friend, is what we call a "slippery slope!" You really don't want to know what happens next, after all, this is a family-friendly site...
* Here's part of the rotten little secret; we humans still couldn't come up with 15 unique 'numbers,' so we started using the other 'counting' system we used in Kindergarten: a, b, c, d, e and f!