The word ‘Mangalsutra’ is derived from the two words, mangal meaning holy or auspicious and sutra meaning thread. It is a necklace that a Hindu groom ties around the bride’s neck in a ceremony called Mangalya Dharanam (Sanskrit for “wearing the auspicious”), which identifies her as a married woman.the wife wears the mangalsutra all her life or till the time the husband is alive as a sign of their marriage, mutual love and goodwill, understanding and faithful commitment to one another.
The mangalsutra,across India, in different parts of the country -(informaion Wikipedia)
thaali (താലി) in Malayalam,mangal sutra (मंगळसूत्र) in Marathi, mangalyasutra (ಮಾಂಗಲ್ಯ), thaali (ತಾಳಿ) in Kannada, and thaali (తాళి), maangalyamu (మాంగళ్యము), mangalasutramu (మంగళసూత్రము) or pustelu (పుస్తెలు) in Telugu, thaali (தாலி) in Tamil. Konkanis (Goans and others, both Hindus and Christians) wear three necklaces around their necks, referred to as dhaaremani or muhurtmani (big golden bead), mangalasutra with one or two gold discs and kasithaali with gold and coral beads. In Andhra Pradesh and Telangana regions, the two coin-sized gold discs are separated by 2-3 beads of different kinds. By tradition, one disc comes from the bride’s family and another from the groom’s side.
Types of Mangalsutra