What do both Diwali and Hanukkah celebratios symbolise?

Both of them is known as the festivals of light but the history behind it is different.

Diwali is celebration celebrated on return of Lord Rama from exile to Ayodhaya.

Hanukkah is an eight-day Jewish holiday commemorating the rededication of the Holy Temple (the Second Temple) in Jerusalem at the time of the Maccabean Revolt of the 2nd century BCE.