Dasha Hara is a Sanskrit word which means the removal of ten bad qualities within you:
Ahankara (Ego)
Amanavta (Cruelty)
Anyaaya (Injustice)
Kama vasana (Lust)
Krodha(Anger)
Lobha(Greed)
Mada (Over Pride)
Matsara(Jealousy)
Moha (Attachment)
Swartha (Selfishness)
Hence, also known as 'Vijaydashami' signifying Vijaya" over these ten
bad qualities.
A different perspective
Ram is your soul.
Sita is your heart.
Ravan is your mind that steals your heart from your soul.
Lakshman is your consciousness, always with you, and act on your behalf.
Hanuman is your intuition and courage that helps retrieve your heart to re-energize your soul