The root of the word Kedoshim is "kodesh", which means "holy" or "sanctified". In the synagogue, the Kaddish prayer has the same root, as does the Kiddush ceremony on Shabbos. "Holy" or "sanctified" can mean, "setting a holy thing apart from an lesser holy thing". That is just what is taking place with the Kaddish prayer in the synagogue, it is separating the different parts of the synagogue service from each other. (Some of these Kaddishes are reserved for morners to say in the merit of the deceased, but they are performing the function of sanctifying different parts of the service nevertheless). Similarly, the Shabbos Kiddush separates the holy Shabbos from the ordinary week preceeding it.

This parsha is called Kedoshim because it presents mitzvahs that serve to sanctify the Jewish people from the other nations.

• The first aliyah begins with G-d commanding Moshe to admonish the Jewish people to be holy, then summarizing several laws such as: fearing parents, observing Shabbos, leaving over parts of the harvested field for the poor, not to lie, not to put a stumbling block before the blind, and others. Not putting a stumbling block before the blind refers to matters such as causing others to sin, or misleading the ignorant, such as saying that something is kosher when it isn't.
  
  
• The second aliyah contains an assortment of commandments: to judge in righteousness, not favoring either the poor or rich, not to go around as a talebearer, not to stand idly by when your neighbor is in danger, not to hate your fellow in your heart, to surely rebuke your neighbor, not to shame him in public, not to take vengeance, not to bear a grudge. And in this aliyah is the commandment to love your neighbor as yourself (which Rabbi Akiva said is a fundamental principle in the Torah).
  
  The following statutes are also given here: not to sow a field with two kinds of seed, or wear a garment made of a mixture of wool and linen which is called shatnez (The checking of a garment for this forbidden mixture is called shatnez testing).
  
  
• The third aliyah contains the laws of "orla" forbidding the fruit of the first three years of a tree and not to mar the corners of the beard. This aliyah also contains the laws forbidding harlotry, sorcery, and tattooing, and admonishing us to observe the Sabbath and G-d's Sanctuary.
  
  
• The fourth aliyah gives the commandment to not harm a converted person; in fact we are commanded to love such a person as we love ourselves. Also here we are commanded to be honest in various weights and measures.
  
  
• The fifth aliyah begins with specifying the penalty for someone who worships Molech; a form of idolatry prevalent in the land of Canaan before the Jewish nation arrived there.
  
  
• The sixth aliyah describes the prohibition against cursing parents, then the prohibitions of adultery and other forbidden sexual relationships including homosexuality, bestiality, and incest, and relations with a woman who is niddah (hasn't yet properly gone to the mikvah).
  
  
• In the seventh aliyah G-d tells us that he has given us a land flowing with milk and honey, and he has separated us from the nations with his commandments. By doing the commandments we connect to G-d and are sanctified and holy, which is what the name of this parsha, "Kedoshim", means.