One difference betwen english and catalan, its that a lot of words in catalan identify who is the subject. In this case if you have invitations in your home, you differs who is coming in your home.
Benvingut----->Its for one man who is arriving at your home
Benvinguda---> For a woman
Benvinguts----> For a grup of people ( It coul be all boys or a grup boys and girls)
Benvingudes ---> For a grup of woman