Assalamu alaikum,

Thank you for your inquiry.

The obligatory (fard) is divided into two, the personal obligatory (fard ain) and the collective obligatory (fard kifayah).

Fard ain is an act that is obligatory for every mature and morally responsible Muslim. An example of fard is the five daily prayers.

Fard kifayah is a collective duty. The duty is considered fulfilled if the community as a whole performs it. Whether it is through the participation of the entire community or a few individuals taking on the task. People who do not participate are not considered sinful as long as the fard kifayah is taken care of by others. However, if there is no one who performs it, the sin falls on everyone in the community. An example of fard kifayah is the funeral prayer (salah al-Janazah).

More about categorization of actions can be read here: Classification of actions

And Allah knows best.

Wassalam
Najeeb ur Rehman Naz