HP ProBook

The HP ProBook is a line of business-oriented laptop computers made by Hewlett-Packard (HP Inc.). HP marketed the ProBook series to business users; the list price was lower than that of HP's higher-end EliteBook series.
History.
S-Series (discontinued in 2012).
In April 2009, HP introduced the ProBook s-series ("standard/essential") notebooks, which consisted of the Intel powered 4410s, 4510s, and 4710s (14", 15.6", and 17.3" screens, respectively) and the AMD powered 4415s and 4515s (14" and 15.6" screens, respectively). This was followed by the introduction of the 13.3" ProBook 4310s in June of the same year. 
The s-series was updated in 2010 with Intel Core i3, i5, and i7 processors, a brushed aluminum case, chiclet keyboard, and multi-touch ClickPad. Updates to the line in 2012 included a new exterior aluminum design.
B-Series (discontinued in 2012).
The ProBook B-series was announced on October 13, 2009, replacing the previous HP Compaq B-series with similar design in early models. All models still have a CD drive bay, docking port, pointstick options, screen latches, draining holes, easy-replaceable battery with additional slice options, TPM chip, socketed CPU, WLAN options and 2 RAM slots.
Two AMD powered models were announced in 2009 — the 14" ProBook 6445b and the 15.6" Probook 6545b; Their Intel powered counterparts were announced three months later as the 14" ProBook 6440b and the 15.6" Probook 6540b.; and the next-year upgrade is a AMD-powered 6455b and 6555b, and Intel-based 6450b and 6550b. 
The B-series design was updated in 2011 with the Intel-powered 6460b and 6560b, and the AMD-powered 6465b and in 2012 with the Intel-powered 6470b and 6570b, and the AMD-powered 6475b. The updated sibling EliteBook line had an additional magnesium frame under screen top lid, the keyboard LED-backlight, the aluminum bottom-cover, the 17" workstation version and the additional security options.
M-Series (discontinued in 2011).
HP launched the 5310m in September 2009 as a line of compact mid-range 12" and 13" ProBooks without CD-drive bay. The 5310m was enclosed by an aluminum and magnesium case, weighed under four pounds, and was less than an inch thick. 
The M-series was updated in September 2010 with a 5320m, closely followed with the release of the 5330m in May 2011 which featured a dual-tone aluminum chassis and Beats Audio.
G-Series.
HP launched the G0 series in 2013. The computers are enclosed in an aluminium and magnesium case. The G1 series succeeded in 2014.
The first digit is a class of laptop (4## — entry, 6## — mid-class models), second digit is a display size (#3# for 13.3", #4# for 14.1", #5# for 15.6" and #7# for 17.3"). The third is an additional mark, like a ##5 for AMD-based model.
G1.
This line have a low-end siblings (15.6" HP 350 G1 and 14.1" HP 340 G1). The 4## models is entry line. and 6## is a mid-range models with aluminum and magnesium case.
G2.
This line have similar siblings.
G7.
HP ProBook x360 435 G7 13.3-inch 2-in-1 was announced on January 16, 2020.
G8.
These are the ProBooks that have been released in Generation 8.
See also.
Competing laptop lines include: