What is the difference between $var and $var ?

Question

What is the use of $var in PHP ?

Answer 1

$ allows you to use the value of a variable as the name of another.

$var = "foo";
$var = "bar";
echo $foo;

Answer 2

variable treat the value of another variable ast it name
$a=`hi'
$hi='hello'
echo$a

Answer 3

For example if,
$thisVar is holding value "otherVar"
and
$otherVar is holding value "Hello i'm other var"

and then when echo value of $thisVar using var var
syntax $thisVar, the resulting value will be "Hello i'm
other var" bcoz $thisVar is holding the name of otherVar.