In this book, thermo-physical and structural properties of technologically important phosphate and silicate glasses/glass-ceramics have been investigated. An attempt has been made to correlate the thermo-physical properties of these materials with their structural features. This work carried out on sodium aluminium titano-phosphate glasses (NATP), strontium zinc silicate (SZS) and barium zinc silicate (BZS) based glasses and glass-ceramics.