When the word Google entered the Oxford English Dictionary in 2006 it was widely seen as proof that the chirpy US tech firm, with its primary-coloured logo and "do no evil" mantra, had officially captured the zeitgeist of the internet age.

The word alphabet - well that's been around a little longer. As have Google's ambitions for growth - Wikipedia lists 182 acquisitions alone, in addition to the company's core business.

Alphabet Inc - Google's new parent company - will make the tech giant's activities "cleaner and more accountable", said its chief executive (and one of Google's original founders) Larry Page in a blog post announcing the news.

Mr Page admitted that from the outset, some of Google's interests "might seem very speculative or even strange" for the firm.

"We are still trying to do things other people think are crazy but we are super-excited about," he said.

More detail of the surprise restructure is expected in the coming weeks, but here's a brief guide to Alphabet's core areas of activity so far - though not in alphabetical order, just to keep you on your toes.

Google

Google itself will continue to exist as a subsidiary of Alphabet under the leadership of a new CEO, but long-term Google exec, Sundar Pichai.

It will include Google's most obvious - and profitable - internet outlets such as search, Maps, YouTube, Chrome and the Android mobile phone platform.

Google X

This is Google's research and development lab, where projects like the driverless car, drone delivery service Project Wing and Project Loon, an ambitious idea to connect rural communities to the net via a global network of high-altitude balloons, are born and nurtured.

Last year pharmaceutical giant Novartis agreed a deal to work with Google X on a smart contact lens for people with diabetes, designed to measure the level of glucose in the wearer's tears and communicate the information to a mobile phone or computer.

The division is is notoriously tight-lipped about much of its work but its web page lists 20 different research areas including artificial intelligence, data mining, software engineering and cryptography.

It refers to some of its more outlandish projects as "moonshots" - a Google X code word for big-thinking propositions.

Calico

Google launched a separate health-focused research and development company in 2013, with Larry Page announcing in a blog post that its work would be based around the research areas of "health and well-being, in particular the challenge of ageing and associated diseases".

"We are scientists from the fields of medicine, drug development, molecular biology, and genetics," says the firm on its website.

"Through our research we're aiming to devise interventions that slow ageing and counteract age‑related diseases."

Nest

Google bought thermostat maker Nest Labs for $3.2bn (£2bn) in early 2014.

Nest's first major product, the thermostat, was able to learn about users' behaviour and decipher whether a building was occupied, but it has since branched out into other areas of smart homeware.

This has included, most recently, a camera that senses movement in a user's home and alerts them via a smartphone app.

Fiber

Google Fiber is a superfast broadband and TV-on-demand service, promising speeds of up to 1,000 megabits per second. It's currently only available in certain parts of the US, including Atlanta, Nashville and Salt Lake City.

Google Robotics

It is unclear whether Google's robotics work will also become a more separate entity under Alphabet Inc.

Google snapped up six robotics companies in 2013 - including military robot-maker Boston Dynamics which developed Cheetah, the world's fastest running robot.

However the tech giant has been clear that none of its robots will be used for military means.

"With fears mounting about Google's wealth, power and knowledge of every aspect of our lives, you can understand why it wanted to give that assurance," said BBC Tech Correspondent Rory Cellan-Jones.

Investment

In addition to its acquisitions, Google has two investment arms - Google Ventures and Google Capital.

Google Ventures claims to have made more than 300 investments alone, with recipients including Uber, Periscope, and Fitstar (which has since been bought by fitness tracker form FitBit).