Another dumb question from the new guy.

[GCUZakalwe]

OK. Resistors, I know what the "K" means at the end of the value but what is the "M" and "R" mean?  I'm sure this have been gone over before and I'm sorry to bring up such basic stuff but I'm  still trying to wrap my head around all the different ways to write the values of resistors and capacitors.  I can read the marking on them ok but the materials lists and other websites keep using different codes that all mean the same thing. 
Thanks for the help guys.

[rullywowr]

Not a dumb question. The M means "mega" and R is used for values under 1K.  These are also used in place of decimal points. For example a 6M8 resistor would be 6.8 Megaohm.  A 470R resistor is just a 470 ohm resistor.

[Coda-effects]

There are no dumb questions,

1 M = 1 000 K =1 000 000 R

It is just a way to abbreviate mega ohm, kilo ohm and ohm