Previously before Summer '16 we are not able to evaluate the next criteria if first criteria is correct.So once the process fall into true condition , implement the action and that's it.It will stop.
In Summer'16 :Processes Can Execute Actions on More Than One Criteria , we able to evaluate next criteria once the process builder process the conditon for current criteria.(ugh ...not sure I am explaining well). It is something like this :
Previously it works something like this.Notice that if condition1 is fulfilled , it will never go to else condition.
Now , we can proceed with next criteria ...it can be like this :
In order for it to evaluate the next criteria, just click on the STOP and it will give the screen shot like below.REMEMBER ,THIS FEATURE DOES NOT WORK FOR SCHEDULE ACTIONS.