RJ45 connector connections are different in LAN cable as compared to cross cable.
E.g.:
Straight Cable
Pin 1 WhiteOrange Pin 1 WhiteOrange
Pin 2 Orange Pin 2Orange
Pin3 WhiteGreen Pin3 WhiteGreen
Pin4 Blue Pin4 Blue
Pin5 WhiteBlue Pin5 WhiteBlue
Pin 6 Green Pin 6 Green
Pin 7 Brown Pin 7 Brown
Pin 8 WhiteBrown Pin 8 WhiteBrown
Cross Cable:
Wire Becomes
1———————-3
2———————-6
3———————-1
6———————-2
By default the LAN Cable is 100 Meters but you may observe drop of signals after 80 Meters.
Cross cable is used to connect two computers without using switch.