Any info on V$STATNAME?

Does anyone have or know where to find documentation on the V$STATNAME table?

I find it useful to join this with V$SESSSTAT like:

	SELECT VALUE, A.STATISTIC#, NAME 
		FROM V$SESSTAT A, V$STATNAME B
		WHERE SID = <some sid#> AND A.STATISTIC# = B.STATISTIC#;

Some of the resulting statistics are pretty obvious, but others are a bit of a mystery to me. If anyone has a short explanation of these, including what units are being used, I'd find it very helpful!

For example, for the following statistics, what do these mean? What are the units, especially for 'waits'?

STATISTIC# NAME

---------- -------------------
         32 db block changes
         33 change write time
         35 write complete waits
         65 redo size

Thanks...