What is Kitchen God and what is Nian?

The Kitchen God, known an "Zao Jun" in Chinese, is a diety in Chinese folklore who is responsible for a family's health and well-being. Traditionally, people keep a shrine for him in the kitchen. He is believed to hold the power to report to the Supreme God how the family has been behaving during the year, according to which the family would be awarded with good luck or punished. Therefore, people see the Kitchen God as a powerful diety. A festival in which people bring offerings to him falls on the last month of the lunar year.

"Nian" may mean many things in Chinese language. Since Chinese is a tonal language and its written form is made up of characters with a complicated pictorial system, there are literally more than a hundred characters, each meaning different things, that may be transliterated into "Nian" in English.
For example, nian may be referring to "year". In traditional folklore, "nian" is also a diety. The folklore goes that "nian" was an unpopular diety. People's practice to scare him off has come all the way to become the routines during the Chinese new year as we observe now.

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Nian may be referring to "year". Traditional folklore goes that "nian" was the name of an an unpopular diety. Some rituals that were intended to drive him away has come all the way to become the routines during the Chinese new year we observe now.