Sandhi

Sandhi ('joining') is the set of sound changes that occur where two words or word-parts meet in Sanskrit, for example deva + ālaya becoming devālaya, or iti + api becoming ity api. Pāṇini's rules distinguish vowel sandhi (ac), consonant sandhi (hal) and visarga sandhi. Because written Sanskrit applies sandhi across word boundaries, undoing it (sandhi-viccheda) is a first step in reading a text.