The input are some numbers, 12, 25,11,28,14
they are unsorted.
temp = 12 (the first element of your list)
for I = 2 to n
if temp <a_i (temp < a_2, that means i.e. if 12 < 25, then)
then temp := ai
temp = 25
well, i know this is not a good explanation, but this program searches a list (input) and the output is the biggest number (here 28)