Hinduism is supposed to be of impersonal origin and so are the Gods of Hinduism. They are eternal & though the deities appear to be different & independent, they are really facets of the same Brahman, the Supreme God.
As noted Saint Sri Ramakrishna says, there can be as many spiritual paths as there are spiritual aspirants & similarly there can really be as many Gods as there are devotees to suit the moods, feelings, emotions & social background of the devotees.
The Hindu scriptures were eloquent while describing the qualities of God. He is all-knowing & all powerful. He is the very personification of justice, love & beauty. He is ever ready to shower His grace, mercy & blessings on His creation.
The main Hindu Gods as we accept today can be broadly classified as Saiva Gods (Shiva, His consort, His sons, His other forms), Vaishnava Gods (Vishnu, His consort, His various avatars or incarnations)& Sakthi or Saktha (Forms of Goddess Sakthi).