how does range function work in python code example

Example 1: for i in range start

for i in range([start], stop[, step])

Example 2: range in python

#range(start,stop,step)
for x in range(0,20,2):
  print(x)

Example 3: range(n,n) python

# if numbers are same in the range function then,
# the range function outputs empty range
# this is because, there are no integers b/w n and n
for i in range(1,1):
  print("runs")

# prints nothing