deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
The word /ca means "and".
It is an enclitic. So it is aded AFTER the word — mAjarAz ca माजराश्च means "and a cat".
zvA श्वा "a dog"
zvA mArjAraz ca श्वा मार्जारश्च "a dog and a cat"
zvA mArjAraz ca madyazAlAm pravizataH श्वा मार्जारश्च मद्यशालां प्रविशतः "a dog and a cat walk into a bar"
The word /vA means "or" and is enclitic too.
zvA mArjAro vA श्वा मार्जारो वा "a dog or a cat"
In sUtras, however, it means "optionally" and it is fine to use it at the very start of a sUtra. See vAzari, vAmzasoH, vAchandasi.