For decades people have spent the majority of their working lives sitting in offices.
But while offices are still commonplace, today's workplace has very little in common with that of our grandparents' generation. Typewriters have given way to computers, computers and phones have shrunk down to devices we can carry in our pocket and ubiquitous internet means work is always with us, for better or worse.
The contribution of modern technology to each worker's productivity is nearly five times greater today than it was in the 1970s, according to a study by the Centre for Economic and Business Research, conducted on behalf of telecoms operator O2.
This scene captures the office of the 1950s and 1960s, from the solid metal Remington typewriter to the bulky Bakelite hand-dialled telephone. The receptionist would generally have operated the switchboard and routed all of the calls.
The mock-up is part of an exhibition showing the evolution of the office over the past 40 years to mark the launch of The O2 Business Show Live in the Business Design Centre in Islington, London.
In the 50s and 60s, the typewriter, 100 years old at the time, was a standard piece of equipment in the office. Computers were still in their infancy and IBM was establishing the Selectric as the de facto standard typewriter in offices, replacing the raucous clack of the older typebar machines with its quieter gyrating typeballs.
Workplace roles were more unequal than today, with women generally employed to do the typing for men.
At the time the annual UK salary was just over £100, with 70 percent of British workers employed in manual labour. It wasn't until this time that it became the norm in Britain to work five days a week rather than six.
A close up of the Remington typewriter.
The rather staid beige and brown décor of the 1970s contrasted with leaps forward in technology.
As more calculator logic was squeezed onto fewer integrated circuits, electronic calculators became small and cheap enough to find their way onto many office desks.
Meanwhile, cassette tape and dictaphones provided new ways to record and access information.
Carbon paper was also cheap enough that multiple copies of a document could be typed in a single sitting, and the advent of electric typewriters made the process even easier. Correction fluid, such as Tipp-Ex, meant minor typographical errors could be corrected easily, reducing the need to retype an entire document.
Office layouts were being simplified, with designers working their furniture schemes around what was called the G-plan.
One of the first executive toys to creep onto desks during this time was the Newton's Cradle.
An electric Smith-Corona typewriter next to a telephone index book with an A-Z slider.
By the 1980s the modern office was becoming recognisable.
The advent of the PC meant the computer moved from a room in the basement to sitting on the desktop.
Personal computers such as the IBM PC (seen here), the Commodore 64, and the Macintosh 128K introduced a step change in how knowledge was processed.
Not that long before the August 1981 debut of the IBM PC, an IBM computer often cost as much as $9m, as well as requiring an air-conditioned quarter-acre of space and 60 people to run and keep loaded with instructions. In contrast, the IBM PC could process information faster than a 1960s mainframe, for a price tag of less than $1,600.
However, computing technology was still relatively crude by today's standards. In 1980 1GB of hard disk space cost £120,000 in today’s money — compared to about 5p today.
In 1983, the world's first commercial handheld cellular phone, the Motorola DynaTAC 8000X, was also released. A caller could talk for 30 minutes and the LED display and memory could store 30 dialling locations. Bulky mobile phones with a short battery life began to be adopted by managers.
The decade also saw fax machines, printers and push button phones taking over the office.
A close-up of an IBM PC running a WordStar word processor application.
The 1990s saw the birth of the mobile working culture that is prevalent today.
Bulky laptops started to become more common, mobile phone ownership rocketed — to half of the UK population by the end of the decade — and the PalmPilot popularised the concept of a handheld PC.
The barrier to using PCs was lowered as refinements to operating systems and more intuitive GUIs made them increasingly easier to use, with Microsoft introducing the Start-based desktop familiar today with the release of Windows 95.
The World Wide Web first became available to the public in 1991 and by 1996 more than nine million people were connected to the internet, with email and internet use spreading throughout workplaces during the latter half of the 1990s.
An early Nokia mobile phone.
The once-ubiquitous fax machine.
Some of the technology that is now commonplace in the modern office.
Today widespread use of internet-connected mobile computers such as laptops, tablets, and smartphones have in some ways made the office less relevant than it once was. Work can be carried out at home or on the move and is no longer so tightly tied to a regular working day.
"You've seen a massive drop in the cost of technology, a massive improvement in its quality and in the interaction between technologies — which means these technologies are far more effective today," said Colm Sheehy, of the Centre for Economic and Business Research, on the evolution of office technology over the past 40 years.