It is a salt, produced by the. neutralization reaction between a strong base (NaOH) and a weak acid (H2CO3), hence it is a basic salt.
It is heated strongly to produce sodium carbonate
2NaHCO3 +heat →Na2CO3+H2O+CO2.
Sodium carbonate is recrystallized to produce washing soda.
Na2CO3 + 10H2O →Na2CO3.10H2O