Izzat is honour, standing, respectability. It is held by a family rather than by an individual and it is damaged by what any member of the family does.
It governs a great deal of Punjabi social behaviour: what is spent on a wedding, what is not discussed outside the house, who a daughter may marry, whether a family reports a crime, and whether a person seeks help.
It is the mechanism behind dowry inflation, behind the concealment of domestic violence and mental illness, and behind so-called honour killings, which occur in Punjab and are reported as accidents or suicides.
It is also what holds a great deal together: reputation as a form of credit, the reason obligations are met and promises kept in a society where the formal enforcement is weak.
Punjabi has no word for the concept in the neutral sense that English uses reputation. Izzat carries the weight of both the good and the damage, which is why it appears in every folk song and every court case.
Izzat is honour and it is held collectively. What one member of a family does affects the standing of all of them, and the standing is what determines the marriages available.
It is the mechanism behind a great deal that is good in Punjabi village life, including the obligation to hospitality and to keeping one's word, and behind a great deal that is not.
The worst of it falls on women. Honour killings are reported in Punjab, as they are across the region, and the cases that reach court are a small fraction.