While loop VS for loop in PHP

For loop

for (start value ; End value; Increment){
//do something
}

Example:
for ($a = 10; $a <100 a="" br="" echo="">";
}

While loop

start value 
while (End value){
//do something
Increment 
}

Example:
$a = 10;
while ($a<100 a="" br="" echo="">";
$a = $a +10;
}