IP Subnetting (pick-note)

Notiff:
Below set of numbers and terms are used in network engineering, so it might not using blog friendly language to understand.

Prefix			Subnet		Wildcard		# Client
							Length		Available
/	16		0.0		0.0.255.255		65536		65534
/	17		128.0		0.0.127.255		32768		32766
/	18		192.0		0.0.63.255		16384		16382
/	19		224.0		0.0.31.255		8192		8190
/	20		240.0		0.0.15.255		4096		4094
/	21		248.0		0.0.7.255		2048		2046
/	22		252.0		0.0.3.255		1024		1022
/	23		254.0		0.0.0.255		512		510
/	24		255.0		0.0.0.255		256		254
/	25		255.128		0.0.0.127		128		126
/	26		255.192		0.0.0.63		64		62
/	27		255.224		0.0.0.31		32		30
/	28		255.240		0.0.0.15		16		14
/	29		255.248		0.0.0.7		8		6
/	30		255.252		0.0.0.3		4		2
/	31		255.254		0.0.0.0		2		0
/	32		255.255		0.0.0.0		1		-1