Which group does the spider belong?

I'm not sure how you mean "Group." Spiders are all members of the order called Araneae and above that in the class called Arachnida.

Most spiders are solitary animals that approach other spiders only to eat them, to fight with them (males of certain species), or to mate. Mother spiders keep their young with them for a shorter or longer period of time, depending on the species. After the baby spider's original store of nutrients becomes exhausted and the babies become hungry, they would cannibalize each other if they were not to disperse.

There are a few species that tolerate close proximity. Some spiders exhibit a great difference in size. The females are huge in comparison to the males. In these species, a female will often tolerate a male to live close by.

In the case of species of spiders that tolerate close proximity of females and may make a sort of group web in which each spider patrols its own part, the group of spiders is called a colony.