Like its 27-inch LED Cinema Display predecessor, the resolution of the 27-inch model is 2560×1440 pixels, and follows a aspect ratio. It was made with aluminum and glass, having a similar appearance to the current ranges of iMac and MacBook Pro unibody designs. The display featured a built-in 720p FaceTime HD camera, microphone, and stereo speaker system with subwoofer. An octopus cable combining Thunderbolt and MagSafe is permanently attached to the back of the display for data input and charging laptops, respectively. There is also a separate Thunderbolt port, a FireWire 800 port, three USB 2.0 ports, and a Gigabit Ethernet port. The Thunderbolt port allows for the possibility of daisy chaining Thunderbolt Displays from a supported Mac, or connecting other devices that have Thunderbolt ports, such as external hard drives and video capture devices. Apple released Rev B of the Thunderbolt Display which includes a MagSafe to MagSafe 2 adaptor to the charging cable built into the display. On June 23, 2016 Apple announced through a statement that it was discontinuing the Thunderbolt Display and would no longer produce stand-alone displays, saying "There are a number of great third-party options available for Mac users." Apple subsequently worked with LG to design the Thunderbolt 3-enabled UltraFine line, consisting of4K and 5K displays. On April 5, 2018 Apple announced that it would re-enter the standalone display business in 2019 by releasing a new display with a new version of the Mac Pro. On June 3, 2019, Apple announced the Pro Display XDR.
Apple Thunderbolt Displays, like the video input on Thunderbolt iMacs, drop compatibility with all previous standards, including VGA, DVI, and DisplayPort. They are not compatible with computers that do not have a Thunderbolt port, including pre-2011 Macs and the vast majority of desktop PCs. As of April 2018, MacBook 12" laptops only have a USB-C port, which cannot communicate with a Thunderbolt adapter. However, newer MacBook Pros and MacBook Airs have Thunderbolt 3 ports. Although these ports have the same connector as USB-C, they are compatible with the Thunderbolt protocol, and can use a Thunderbolt Display with a Thunderbolt 3-to-2 adapter.
Using multiple displays
MacBook Pro
Macbook Pro : 2 Displays: Can daisy chain two Apple Thunderbolt Displays together to get two displays, but the laptop's LCD may turn off.
Macbook Pro : 2+2 Displays: Can daisy chain two Apple Thunderbolt Displays, in addition to one HDMI display and the Macbook Pro's own display, for four displays total
MacBook Pro : Apple released a for enabling the Thunderbolt 3 ports of MacBook Pro to connect to Thunderbolt 2 devices.