It is a huge topic and we always end up in confusion. I will explain what is the reality in simple terms, subject to the limitation of my knowledge and experience.
Brahman has two aspects. One is Brahman without attributes (nirguṇa) and another is Brahman with attributes (saguṇa). Nirguṇa Brahman is the source of eternal light. Light is also an attribute. Then why we call Nirguṇa Brahman as the one without attributes. Under normal human consciousness, we can can only realize light. A minuscule form of this light is what we see during our meditation. The light that we see is not as pure or as powerful as it should be, because its original power is is subdued by its own power. Why this light is subdued? We cannot withstand its original intensity, as it is too hot and too powerful. The power of subjugation is known as māyā, which is not different from Brahman. This is merely its own Power. When we try to realize Nirguṇa Brahman, first we have to realize saguṇa Brahman. How to realize saguṇa Brahman? This is where our meditation and spiritual inquiries help. Saguṇa Brahman can be realized when we are able to work on our mind, consciousness and breath. Nothing else apart from the three will help. Unless we move from external worship to internal contemplation, we cannot enter into spiritual path. Devotion is something different from Love for the Divine. In devotion, we worship some form in a higher pedestal. Whereas in Love, we contemplate that form within. In the latter case we become closer to that form. This form will also dissolve when we work on mind, consciousness and breath. Now Saguṇa Brahman takes us to Nirguṇa Brahman. In other words, when we understand and realize māyā, we realize Nirguṇa Brahman.
What happens then? When these forms get dissolved, we begin to see some light, feel vibrations in our body, secretion of Divine nectar, etc. At this stage we gradually get disconnected from sensory organs and we try to work more with the above three. At the end of this process, we see bright illumination, our consciousness moves out of our body through brahmarandra and we enter into the fourth and fifth states of consciousness, Turya and Turyaatiita. There are two types of realizations. One is the realization of the Self within which we call as Self-realization and another is universal realization, where we consider the entire universe as the Self (aham and idam or I and this, where I refers to the Self within and this refers to the universe). This is with regard to Self realization. But this is not Liberation. Why this is not Liberation?
When you say I am Brahman, the trace of ego is still there. If ego is not there, then how do you say "I am" Brahman. Many will disagree here, but even at this stage there is a trace of duality. If duality is not there, then why should you say "I am" Brahman. However, this is the stage most of us can reach. But this is different from Liberation.
Then what is Liberation? It is nothingness, it has no attributes, no light, nothing at all and this is known as "mahāśūnya", known as great void. This terminology is used in Buddhism. Mahāśūnya is nothing but supreme void, it is not even darkness, it is beyond darkness where stillness and silence alone prevail. This is what is known as "Parabarahman". This is the "place" for Liberation.
Let us put this discussion in this way. Śakti is Saguṇa Brahman, Shiva is Nirguṇa Brahman and Paramashiva is Parabarahman. This comparison is only for the purpose of understanding. First we have to realize Śakti and through Her Grace, we realize Shiva and finally, subject to our karmic account, we get liberated in Paramashiva.