what are vin_sz and vout_sz in tx part? I am trying to understand the raw blocks better:

vin_sz and vout_sz are some of the unknowns. does this values (sz=size?) have something to do with a number of confirmations?

example:
https://blockexplorer.com/rawblock/00000000000008d11f13eed2e13f2765eceaf00de36e0ec040a10cc3738bdc74
I believe it stands for vector input size and vector output size.

vin_sz is the number of inputs and vout_sz is the number of outputs.