No, they are not the same!
God is the supreme fundamental entity, known as Brahman (not Brahmā), from which everything in the universe, including the universe itself, comes forth:
yato vā imāni bhūtāni jāyante yena jātāni jīvanti
yatprayantyabhisaṃviśanti tadvijijñāsasva tadbrahmeti [Tait. Up. -
3.1]
Meaning
That from which all these beings are born, having born by which they live, That into which having departed they enter, seek to know
That, That is Brahman.
janmādyasya yataḥ [Brh. Su. - 1.1.2]
-- From where origin etc. take place.
While God is the cause of the universe, devi-devta (gods and goddesses) are part of the universe itself. Hence, God is the source of all gods, goddesses and sages:
aham ādir hi devānāṁ maharṣīṇāṁ ca sarvaśaḥ [BG -10.2]
I am indeed the source of gods and sages in every respect.
Some differences
They are not eternal and came into existence just like us. Just like we exist on bhu-loka (earth), they are believed to exist in the swarga-loka (heaven). While God is the Supreme Being, gods and goddesses are one kind of higher beings like the pitaras (manes). While all of us, including the gods and higher beings are under the influence of māyā (illusion), God is the lord of māyā:
mama māyā duratyayā [BG - 7.14]
My illusory energy is difficult to overcome.
māyinaṃ tu maheśvaraṃ [Sve. Up. - 4.10]
But God is the lord of māyā
While gods and goddesses are propitiated by sacrifices and rituals, God being the source of everything needs nothing from us. But if one wants to attain God (parameswara), then only through devotion He can be achieved:
na sādhayati māṃ yogo na sāṅkhyaṃ dharma uddhava
na svādhyāyas tapas tyāgo yathā bhaktir mamorjitā [SB - 11.14.20]
Meaning
Neither yoga brings Me under control, nor knowledge and virtue. O Uddhava, neither study of the scriptures, nor penance and renunciation brings Me under control like unalloyed devotion to Me does.
Number of God and gods
God being the supreme fundamental entity is one without a second:
ekam advitiyam brahma [Chg. Up - 6.2.1] - Brahma is one without a second
brahmaitad advitīyaḿ [SB - 11.9.31] - This Brahma is one without a second
But gods and goddesses of higher planes of existences being manifested beings just like us, are innumerable in number. However, just like we have a countable number of authorities (presidents or prime ministers) for every country, there is a specific number of gods who have authority over many aspects of our world. The scripture [Brihadaranyaka Upanishad - 3.9] gives the number as thirty three (33) and states that the other form of gods (3306) are just their powers:
कतमेतेत्रयश्च त्रीच शतात्रयश्च त्रीच सहस्रेति
Which are the three
hundred three and three thousand three gods?
सहोवाच महिमान एवइषामेते,त्रयस्त्रिंशत्त्वेवदेवाइति
He (Yajnavalkya) said, "Those are their powers, but gods are only thirty three."
कतमेतेत्रयस्त्रिंशदित्य्
Which are the thirty three?
अष्टउवसव ,एकादश रुद्रा ,द्वादशादित्यास् , तएकत्रिंशद् , इन्द्रश्चैवप्रजापतिश्च त्रयस्त्रिंशाविति
Eight Vasus, eleven Rudras, twelve Adityas. These are thirty one, Indra and Prajapati make it thirty three.