This is the 7960th most frequent Russian word.
коллективная
"Collective."
Here, "коллективная" (collective) is an adjective describing the type of work that is done by a group or team rather than individually.
Коллективная работа помогает быстрее достичь целей.
Collective work helps to achieve goals faster.
In this sentence, "коллективный" (collective) is used as an adjective to describe the project as one undertaken jointly by every member of the team.
Это был коллективный проект всей нашей команды.
It was a collective project of our entire team.
Here, "коллективного" (collective) functions as an adjective describing the solutions, indicating that they involve the effort and agreement of a group.