gistfile1.txt

given:
a = 1
b = 2

------------

if (a == 1):
  print "a is 1"
if (b == 2):
  print "b is 2"
  
# result: both lines are printed
  
------------

if (a == 1):
  print "a is 1"
elif (b == 2):
  print "b is 2"
  
# result: ONLY the first line is printed - because of the "else" in elif. "do this, else do this."