MacBook

The MacBook is a brand of Macintosh laptop computers by Apple Inc. that merged the PowerBook and iBook lines during Apple's transition to Intel processors. The current lineup consists of the MacBook Air (2008–present) and the MacBook Pro (2006–present). A different MacBook line existed from 2006 to 2012 and 2015 to 2019.

Overview
The MacBook family were initially housed in designs similar to the iBook and PowerBook lines which preceded them, now making use of a unibody aluminum construction first introduced with the MacBook Air. This new construction also has a black plastic keyboard that was first used on the MacBook Air, which itself was inspired by the sunken keyboard of the original polycarbonate MacBooks. The now standardized keyboard brings congruity to the MacBook line, with black keys on a metallic aluminum body.

The lids of the MacBook family are held closed by a magnet with no mechanical latch, a design element first introduced with the polycarbonate MacBook. Memory, drives, and batteries were accessible in the old MacBook lineup, though the newest compact lineup solders or glues all such components in place. All of the current MacBooks feature backlit keyboards.

The MacBook was discontinued from February 2012 until March 2015, when a new model featuring an ultraportable design and an all-metal enclosure was introduced. It was again discontinued in July 2019 following a price reduction of the 3rd generation MacBook Air and discontinuation of the 2nd generation model.

MacBook Air
The MacBook Air is Apple's least expensive notebook computer. While the 1st generation was released as a premium ultraportable positioned above the 2006 - 2012 MacBook, lowered prices on subsequent iterations and the discontinuation of that MacBook has made it serve as the entry-level Macintosh portable. The 2010 to 2017 base model came with a 13-inch screen, and was Apple's thinnest notebook computer until the introduction of the MacBook in March 2015. This MacBook Air model features two USB Type-A 3.0 ports and a Thunderbolt 2 port, as well as an SDXC card slot (only on the 13inch model). This model of MacBook Air did not have a Retina Display. A MacBook Air model with an 11-inch screen was available from October 2010 to October 2016. In 2017, the MacBook Air received a small refresh, with the processor speed increased to 1.8 GHz.

On October 30, 2018, the MacBook Air underwent a major design change, dropping the USB Type-A ports, MagSafe, and the SD card slot in favor of two USB-C/Thunderbolt 3 ports and a headphone jack. It was updated with a Retina display and Intel Y-series Amber Lake i5 CPUs, as well as a Force Touch trackpad, a third generation butterfly mechanism keyboard, and the Touch ID sensor found in the fourth generation MacBook Pro, but without the Touch Bar. The base price was also raised, although the base configuration of the 2017 model was retained until July 9, 2019, when it was discontinued along with the Retina MacBook. The base price of this model was also dropped to $1099 ($999 for students) on the same day.

MacBook Pro
The MacBook Pro is Apple's higher end laptop available in both 13-inch and 16-inch configurations as of November 13, 2019. The current generation 13-inch MacBook Pro was introduced on October 27, 2016, which is thinner and lighter than the third generation MacBook Pro. It features a touch-sensitive OLED display strip located in place of the function keys, a Touch ID sensor integrated with the power button, a butterfly mechanism keyboard similar to the MacBook, and four USB-C ports that also serve as Thunderbolt 3 ports. The 13-inch model was also available in a less expensive configuration with conventional function keys and only two USB-C/Thunderbolt 3 ports, but since July 2019, the base MacBook Pro model has the Touch Bar as well as quad-core processors, similar to the higher-end models, although it still has only two USB-C / Thunderbolt 3 ports.

On November 13, 2019, Apple released the 16-inch MacBook Pro, replacing the 15-inch model of the previous generation, and replacing the butterfly keyboard with a scissor mechanism keyboard (dubbed the Magic Keyboard by Apple), reverting to the old "inverted-T" arrow key layout, replacing the virtual Escape key on the Touch Bar with a physical key, and replacing the AMD Polaris and Vega graphics from the 15-inch model with options from AMD's Navi graphics architecture, as well as reengineering the speakers, microphone array, and the thermal system compared to the 15-inch; the latter had thermal limitations in the 15-inch model due to its design. In addition, the 16-inch is available with up to 64 GB of DDR4 2667 MHz RAM and up to 8 TB of SSD storage. It also has a 100 Wh battery; this is the largest battery that can be easily carried onto a commercial airliner under U.S. Transportation Security Administration rules.

Discontinued
The original MacBook was a line of Macintosh portable computers introduced in May 2006 that served as entry-level laptops following Apple's transition to Intel processors, replacing the iBook G4. It was discontinued on July 20, 2011 for consumer purchase and in February 2012 for education institutions, being superseded by the 2nd generation MacBook Air, as the 11-inch model introduced in 2010 had the same starting price of the MacBook.

The Retina MacBook was a line of Macintosh portable computers introduced in March 2015. It was discontinued on July 9, 2019, as it had been superseded by the 13-inch Retina MacBook Air, which had a lower base price ($1299 for the MacBook, $1199 for the 2018 MacBook Air, and $1099 for the 2019 MacBook Air), additional USB-C / Thunderbolt 3 ports (the MacBook has only one USB-C port vs two USB-C / Thunderbolt 3 ports on the MacBook Air), and better performance.