Differents between rand() / mt_rand () in PHP

rand() :

          Slow process, max allowed length smaller than mt_rand(), may has dubious or unknown characteristics, can get max limit by getrandmax(), using old technique.

          Syntax:  int rand(min,max);
          Example: echo rand(0,500);         // return value between 0 to 500 (including 0 and 500)

mt_rand():

         Four times faster than rand(), had large max length, return known characteristics, can get max limit by mt_getrandmax().

          Syntax:  int mt_rand(min,max);
          Example: echo rand(100,99999);         // return value between 100 to 99999

Conclusion:

          In my point of view mt_rand() is better than rand() in any cases.