Connection Timeout and Connection Lifetime

What is the advantage and disadvantage of connection timeout=0?

And what is the use of Connection Lifetime=0?

e.g

(Database=TestDB;
 port=3306;
 Uid=usernameID;
 Pwd=myPassword;
 Server=192.168.10.1;
 Pooling=false;
 Connection Lifetime=0;
 Connection Timeout=0)

and what is the use of Connection Pooling?