basically terminal is a file that program can read or write.
major number = 8
identifies the driver associated with the device. for exmaple , /dev/null and /dev/zero are both managed by drvier 1, whereas virtual consoles and serial terminals are managed by driver 4.
minor number = 0,1,2
used only by the drvier specified by the major number. the minor number provides a way for the driver to differentiate among them.
Terminal Attribute
highphone(-) means values is OFF , e.g) echo is ON
Real time = is defined as time measured from some fixed point, either from a standard point in the past or from some point in the life of process(elapsed time)
Process time = is defined as the amount of CPU time used by a process.
real time clock(rtc) = hardware clock ,cmos clock, can run even system is off
system clock = sofware clock ,kernel clock , cannot run when system is off , when booted it needs to be intiailze
locale is a subset of a user's environment that depends on language and cultural convetions