diference between signal and variable?

[jonathan castro]

good morning

can someone explain me the diference between use a signal and a variable?

is there a pysic diference between them both?

 

[jeppe]

Find and download Evita VHDL interactive book - In chapter 6 will you find examples which explains the difference.

A variable will get its value immediate with :=
A signal will wait until the code ended <=