This is the 2668th most frequent Russian word.
этапов
Stages.
The word 'этапов' here is the genitive plural form of 'этап,' meaning 'stage,' and is used to indicate multiple stages of a project.
Проект состоит из нескольких этапов.
The project consists of several stages.
In this sentence, 'этапов' is again in the genitive plural, used to describe the aspects belonging to or related to the stages.
Планирование включает в себя все необходимые аспекты этапов.
Planning includes all the necessary aspects of the stages.
Here, 'этапов' denotes the stages that need to be completed, again in the genitive plural form to indicate possession or relationship.