OK, take a deep breath and get out your Hebrew lexicons.
Chapters 17 - 26 of Leviticus are a distinct unit of the Bible, with a unique writing style: the dominant theme being holiness. The section was called the “Holiness Code” by A. Klosterman in 1877. The central idea of the Holiness Code is that the people of Israel bears a collective responsibility to try to achieve holiness (Lev 19:2 “You shall be holy for I, the Lord your God, am holy.”)
If that’s enough of an answer, I suggest you stop reading now.
The concept is that of a holy people, and the laws are addressed to all of Israel, not only to Moses or Aaron or the priesthood. The Holiness Code covers:
Chapter 17 - Prologue; on proper modes of worship
Chapter 18 - Rules of forbidden sexual unions (abominations)
Chapter 19 - Code of religious and secular laws pertaining to the land (agriculture, testimony, social ethics, etc.)
Chapter 20 - A legally formulated restatement of Chapter 18, with some additions
Chapter 21:1 - 22:16 - Rules governing the priesthood in matters of marriae, ritual purity, etc
Chapter 22:17 - 33 - Requirements for sacrificial animals
Chapter 23 - Liturgical calendar of sacred occasions
Chapter 24 - Laws about ritual and blasphemy
Chapter 25:1 - 26:2 - Laws governing agriculture and ownership of the land
Chapter 26:3 - 46: Epilog, blessings and curses
The Biblical concept of “holiness” is hard to define: it’s a mysterious quality, a separateness, an “other.” The presence of holiness may inspire awe or strike fear or evoke amazement. The holy is both dangerous and desirable.
In biblical literature, there is a curious interaction between the human and the divine with respect to holiness. The Israelites are commanded to make the sabbath holy (Exodus 20:8), but verse 11 of the same commandment says that God declared the sabbath day to be holy. The way to holiness (for both individuals and societies) seems to be to emulate God’s attributes.
OK, now we’re drifting away from the historic/literary into the mystical.