There is no discrimination in Buddhism in view of its attainment beyond senses and consciousness. But for the gradual levels of Stillness towards Supreme, Theravada & Mahayana are identified for purpose of understanding and dharma lectures to laypersons.
Theravada or arhat is Stillness. When a being has attained the highest level of Theravada (arhat), the consciousness transformed into Stillness but lack of Wisdom. It means this Stillness has "in & out". This Stillness may be in hibernation for several hundred kalpa or as and when out of Stillness, basically for purpose of liberating beings. Unlike Theravada, Mahayana's Stillness has no "in & out", is in omniscience, known as Wisdom, supreme enlightenment, Ultimate bliss, or Bodhicitta, the quintessence nature of all sentience and Buddhas. Thus, Theravada does not realise Bodhicitta, whereas Mahayana realised and/or actualised Bodhicitta. You may acknowledge or call yourself a Mahayanist, but in fact it depends whether you are truly realised Bodhicitta. Similar to Theravada :)
Do not conflate Theravada with hinayana. One is a tradition handed down by Buddha Shakyamuni ( handful of leaves, so to speak), whilst the other is a mindset.
There is much to learn if one's mind is not closed towards them. For some, they are sufficient, in others not.
The Pure Youth Moonlight arose from his seat, bowed at the Buddha's feet, and said to the Buddha, "I remember that long ago, beyond Kalpas as many as there are sands in the Ganges, there was a Buddha in the world named Water-God, who taught all the Bodhisattvas to cultivate the contemplation of water and enter Samadhi.
"I reflected upon how throughout the body the essence of water is not in discord. I started with mucus and saliva and went on through my body, the nature of water was identical. I saw that the water in my body was not at all different from that in the world outside-even that in royal lands of floating banners with all their seas of fragrant waters.
"At that time, when I first succeeded in the contemplation of water, I could see only water. I still had not gotten beyond my physical body.
"I was a Bhikshu then, and once when I was in Dhyana repose in my room, a disciple of mine peeked in the window and saw only pure water there, which filled the entire room. He saw nothing else.
"The lad was young, and not knowing any better, he picked up a tile and tossed it and into the water. It hit the water with a 'plunk.' He gazed around and then left. When I came out of concentration, I was suddenly aware of a pain in my heart, and I felt like Shariputra must have felt when he met that cruel ghost.
"I thought of myself, 'I am already an Arhat and have long since abandoned conditions that bring on illness. Why is it that today I suddenly have a pain in my heart? Am I about to lose the position of non-retreat?'
"Just then, the young lad came promptly to me and related what had happened. I quickly said to him, 'When you see the water again, you may open the door, wade into the water, and remove the tile.' The child was obedient, so that when I re-entered Samadhi, he again saw the water and the tile as well. He opened the door and took it out. When I came out of concentration, my body was as it had been before.
"I encountered limitless Buddhas and cultivated in this way until the coming of the Thus Come One, King of Masterful Penetrations of Mountains and Seas. Then I finally had no body. My nature and the seas of fragrant waters throughout the ten directions were identical with true emptiness, without any duality or difference. Now I am with the Thus Come One and am known as a Pure Youth, and I have joined the assembly of Bodhisattvas.
Sundarananda arose from his seat, bowed at the Buddha's feet, and said to the Buddha, "When I first left home and followed the Buddha to enter the way, I received the complete precepts, but my mind was always too scattered for Samadhi, and I could not attain the state of having no outflows. The World Honored One taught Kaushthila and me to contemplate the white spot at the tip of our noses.
"From the first, I contemplated intently. After three weeks, I saw that the breath in my nostrils looked like smoke when I inhaled and exhaled. My body and mind became bright inside, and I perfectly understood the external world, to the point that everything became empty and pure, like crystal. The smoky appearance gradually disappeared, and the breath in my nostrils became white.
"My mind opened and any outflows were extinguished. Every inhalation and exhalation of breath was transformed into light which illumined the ten directions, and I attained Arhatship. The World Honored One predicted that in the future I would obtain Bodhi.
"The Buddha asks about perfect penetration. I did it by means of the disappearance of the breath, until eventually the breath emitted light and the light completely extinguished my outflows.
Sentient beings completed submerged and lost themselves into the issues of cycles of birth and death, whereas Theravada completely avoided it; Mahayana neither submerged nor avoided them but facing and adjusting it from its unsurpassed tolerance, benevolence and patience
What is the purpose of practicing Buddhism?