Thunderbolt 2, introduced by Intel in 2013, was the second iteration of the Thunderbolt interface, designed to enhance the data transfer and display capabilities of its predecessor. It doubled the data transfer speed to 20 Gbps by combining two 10 Gbps channels into a single bidirectional channel. This improvement made Thunderbolt 2 suitable for data-intensive tasks like transferring large files, streaming high-resolution videos, and connecting external RAID storage systems and professional audio/video equipment.
https://en.wikipedia.org/wiki/Thunderbolt_(interface)
One of the standout features of Thunderbolt 2 was its support for 4K video workflows, allowing simultaneous transfer of 4K video and data over a single cable. This made it an ideal choice for creative professionals, such as video editors and graphic designers, working with high-resolution media. Thunderbolt 2 retained the Mini DisplayPort connector used in the original Thunderbolt standard, ensuring compatibility with existing devices while delivering enhanced performance.
Thunderbolt 2 also maintained compatibility with PCI Express and DisplayPort, enabling daisy-chaining of up to six devices, such as external hard drives, monitors, and docking stations. While it has been largely superseded by newer standards like Thunderbolt 3 and Thunderbolt 4, Thunderbolt 2 played a crucial role in advancing high-speed connectivity and setting the stage for modern, versatile interfaces used in both consumer and professional environments.
https://www.anandtech.com/show/6122/intels-thunderbolt-update-20gbs-controllers-coming-in-2013