If you Galaxy S5 your contacts have assigned groups on your Samsung and want of such a group to send a text message, this is very easy with the Android news app. This allows a single text message to an entire group to send. Thus, several contacts with an SMS can be achieved. (Note there are several SMS settled).
And as you send on the Samsung Galaxy S5 a message to a group:
Open the Android news app and tap in the summary below right on the plus button to compose a new SMS. In the bar receiver you see on the right a small standard profile picture. Tap on it and it will open a summary screen. Here you can select on the tab:
Favorites
Contacts
Groups
Now switch to the "Groups" tab and then select the group to which the SMS should be sent. You can now select the individuals within a group to which the SMS is sent. You can also select ale contacts to a group by setting the upper left of the checkbox is a catch. Up to 20 contacts can be selected maximum per group.
If you have made your selection, then tap the top right on "Finish". Then you write the text of the group SMS and send the message from.
You now know how to send on the Samsung Galaxy S5, a group SMS.