The word treaty means union. When we pronounce two words side by side , the two letters next to the two words are not often pronounced separately. The two merge. Thus, the union of two castes side by side is called a treaty. Such as- nab + anna = nabanna , vidya + alay = school etc. That is , the union of two castes side by side is called a treaty. Such as - lion + seat = throne , knowledge + home = school etc. How many types of treaties and what are they ? There are three types of treaty mats. E.g. a. Vocal cords b. Consonant c. Heavenly treaty a. Svarasandhi: Svarasandhi is the joint formed between the vowel and the vowel . For example- nab + anna = nabanna (a + a = a). B. Consonant: The conjunction of a consonant or a vowel with a consonant is called a consonant . For example- direction + interior = horizon (a + a = c) etc. C. Bisarga Sandhi: The union of vowel or consonant with Bisarga is called Bisarga Sandhi. For example - nih + akar = amorphous (ঃ + a = ra) etc.