var1=hello
var2=ls -l firstscript
var3="ls -l firstscript"
var4='ls -l firstscript'
var5=`ls -l firstscript`

echo var1 is $var1
echo var1 is "$var1"
echo var1 is '$var1'
echo var2 is $var2
echo var3 is $var3
echo var4 is $var4
echo var5 is $var5