The tichel, also called a mitpachat, is a headscarf worn by many married Orthodox Jewish women in compliance with the code of modesty known as tzniut. Tichels can range from a very simple plain color cotton square with a simple tie in the back to very elaborate fabrics with very complex ties using multiple fabrics. As with any other form of clothing, the tichel is influenced by fashion.
After the wedding ceremony, “Erusin”, some Judaic traditions state that the woman may only show her hair, which is viewed within Orthodox Judaism as a sensual and private part of a woman’s appearance, to her husband in privacy. This is considered a sign of the bond between husband and wife.
The Mishnah in Ketuboth (7:6), however, implies that hair covering is not an obligation of biblical origin. It discusses behaviors that are grounds for divorce such as, "appearing in public with loose hair, weaving in the marketplace, and talking to any man" and calls these violations of Dat Yehudit, which means Jewish rule, as opposed to Dat Moshe, Mosaic rule. This categorization suggests that hair covering is not an absolute obligation originating from Moses at Sinai, but rather is a standard of modesty that was defined by the Jewish community.
The Talmud (Ketuboth 72) presents a compromise position: minimal hair covering is a biblical obligation, while further standards of how and when to cover one's hair are determined by the community.
Elsewhere in the Talmud (Berakhot 24a), the rabbis define hair as sexually erotic (ervah), and prohibit men from praying in sight of a woman's hair. The rabbis base this estimation on a biblical verse: “Your hair is like a flock of goats” (Song of Songs 4:1), suggesting that this praise reflects the sensual nature of hair. However, it is significant to note that in this biblical context the lover also praises his beloved's face, which the rabbis do not obligate women to cover. Though not all would agree, the late medieval commentator, the Mordecai, explains that these rabbinic definitions of modesty - even though they are derived from a biblical verse - are based on subjective communal norms that may change with time.