Short answers, pulled from the story.
Uddaka Rāma was the predecessor of Uddaka Rāmaputta and had reached the highest sphere of meditation. Most traditions preserve the distinction between Uddaka Rāmaputta and his father or teacher Uddaka Rāma.
Uddaka Rāmaputta taught refined states of meditation known as the jhāna formless attainments called arūpa samāpatti in Pali texts. His method focused on quieting the mind until all sensory input faded away so practitioners could enter deeper layers of consciousness beyond physical perception.
The Buddha learned that Uddaka Rāmaputta had already died by the time he attained enlightenment. This timing prevented any direct transmission of teachings between them after the Buddha first thought of him as someone who would be able to understand and realize his Dhamma.
The surviving sources all agree in placing Uddaka Rāmaputta in Rajagriha during the Buddha's lifetime. Hsuan Tsang also recorded legends in his era that associated him with the vicinity of Rajagriha.
Andre Bareau argued that both Uddaka Rāmaputta and Aalara Kalama were fictional creations while later scholars have accepted the possibility that they may have been real historical figures. Scholars continue examining whether these names represent actual people or symbolic representations of spiritual stages.