All together and In a group

All together adverb - Used of a group whose members acted or were acted upon collectively and when `all' and `together' can be separated by other words.

In a group and all together are semantically related in all at once topic. In some cases you can use "In a group" instead the phrase "All together" as an adjective or an adverb.

All together and in a group are semantically related in all at once topic. You can use "All together" instead the phrase "In a group" as an adjective or an adverb.