What is it?

Data halls are the rooms where rows of computers store, process and move digital information - data.

They are the heart of a data centre.

How does it work?

When you use a digital service, it’s often described as living in the ‘cloud’.

Well, the cloud is a good way to explain that data doesn’t live in one place – but it also doesn’t really explain that data must have a computing environment to support it.

So, all the information being processed by a digital service – your phone, your laptop, your TV or streaming service – is enabled by computers, such as these.

Those computers process the request and send the right information back through secure fiber optic networks – the Internet.

That could be opening an app, making a payment, streaming a film, checking a map, sending an email or accessing a work file.

What does it enable?

Data halls house the computers and digital services people use every day, including:

• Your smartphone
• Websites & apps
• Streaming
• Social media
• Online banking
• Contactless payments
• Cloud storage
• Maps and travel software
• Healthcare systems
• Business tools
• Video calls and messaging services
• AI tools – Chat GPT, Claude and Gemini

What do people typically ask?

Is my personal data stored here?

A data centre provides the secure building, power, cooling and connectivity that allow digital services to run. The information stored or processed inside them depends on the companies and services using the equipment.

The role of the data centre is to keep the technology secure, reliable and working 24/7 so digital services can be continually accessible when people need them.

What is it?

Connectivity is the high-speed network that links a data centre to the Internet, telecoms networks, cloud platforms and digital services.

It is the route that transports data in and out of the building.

How does it work?

Data travels through fibre connections between the data centre and the internet’s digital network.

These connections allow services to respond quickly and reliably, whether someone is making a payment, joining a video call, accessing a website or sending an email.

We can still make this simpler, which is a win if Vera from Manchester is worried about the DC on her doorstep

What does it enable?

Connectivity enables digital services to feel instant and work at your fingertips.

It supports:

• Fast websites and apps
• Video calls and instant messaging
• Uninterrupted streaming of content
• Online payments
• Cloud platforms
• Microsoft office and Google apps
• Secure business systems
• Mobile and broadband services
• Real-time updates, such as maps and travel information

What do people typically ask?

Why does a data centre need to be connected to so many networks?

Because digital services need to be fast and come with a guarantee they’ll work when you need them - resilience. The more connected a data centre is, the more efficiently digital information can move between people, devices, businesses and services.

Strong connectivity also removes single points of failure, ensuing digital interactions are as reliable as they can be.

What is it?

The power supply keeps the data centre running. As well as backup generators, this area also houses batteries that enable the data centre to continue to operate in the event of loss of main power.

Data centres need reliable electricity because the services they support are expected to be available around the clock.

How does it work?

Data centre power is planned, purchased and managed separately from household electricity supplies, so people in the UK never need to worry.

A data centre agrees and purchases its power with energy providers in advance. It also uses backup systems (generators) so digital services keep running if there is a power failure.

Some backup systems also use HVO – a 100% renewable fuel made from waste food – in place of diesel or fossil fuels.

What does it enable?

Reliable power helps keep digital services working when people need them.

That includes:

• Websites and apps
• Mobile phones
• Banking
• Healthcare systems
• Payment networks
• Business systems
• Emails
• Cloud services
• Communications
• Public services

What do people typically ask?

Will it affect my electricity bill?

Some UK data centres use large amounts of electricity, but they do not draw power from neighbouring homes and communities.

Power for a data centre is supplied through commercial arrangements agreed, in advance with energy providers. The electricity used by the data centre does not affect the electricity usage or bills of homes in the UK.

Many UK data centre operators buy 100% renewable electricity, which helps support demand for green energy systems.

What is it?

Cooling systems keep servers (computers) and data centre equipment at the right temperature.

Servers generate heat when they work, so cooling is essential to keep the data centre running safely and efficiently.

How does it work?

Modern data centres use carefully designed cooling systems to remove heat from equipment.

In the UK, many newer sites use closed-loop or waterless cooling systems to minimise water consumption.

A closed-loop system works more like a car radiator: liquid moves around the system to transfer heat, but it is not continuously taking water from the public supplies.

In fact, a study of one AI data centre found that uses the same amount of water in a 20-year period, that an average family of four does in a single year.

What does it enable?

Cooling helps keep digital services running.

It protects IT equipment, reduces the risk of disruption and allows systems to operate efficiently.

What do people typically ask?

Will cooling affect my water pressure?

Modern UK data centres are not typically designed to draw large amounts of water from the local supply for cooling.

Where closed-loop or waterless cooling is used, the system will not affect local household water pressure.

What is it?

Backup power systems are there to keep the data centre running if there is a power cut or grid issue.

They are part of the site’s resilience planning and only used in emergencies or for testing.

How does it work?

If mains power fails, backup power systems take over automatically and keep essential equipment running so vital digital service are unaffected.

Generators are also tested regularly to make sure they will work if they are ever needed.

What does it enable?

Backup power helps keep important digital services online.

That matters because people, businesses and public services rely on digital systems being available, or working, all the time.

What do people typically ask?

Are the generators running all the time?

No. Generators are there for emergency backup and testing. They are not the normal day-to-day power source for the data centre.

They may be tested periodically, and those tests are managed carefully to limit disruption.

Do generators cause pollution?

Not always. While some generators run on diesel, others use HVO (hydrotreated vegetable oil) to keep the data centre running.

HVO is a 100% renewable fuel made from waste food and reduces 90% of net CO² emissions.  

What is it?

Security and monitoring systems help protect the building, equipment and services that rely on the data centre.

This includes physical security such as fences, access controls such as IDs, fire protection and real-time monitoring (CCTV).

How does it work?

Only authorised people can access sensitive areas of the data centre.

The site is monitored so teams can detect and respond to issues quickly, whether that relates to access, power, cooling, equipment or fire safety.

What does it enable?

Security helps protect the infrastructure behind the digital services you rely on.

It also supports safe, reliable operation for the businesses and services using the data centre.

What do people typically ask?

Why does a data centre need so much security?

Data centres were legally designated as critical national infrastructure by the UK Government and support highly important digital systems.

The security is there to protect the equipment, maintain reliability and reduce the risk of disruption. It is also one of the reasons data centres are carefully designed and managed.

What is it?

Security and monitoring systems help protect the building, equipment and services that rely on the data centre.

This includes physical security such as fences, access controls such as IDs, fire protection and real-time monitoring (CCTV).

How does it work?

Only authorised people can access sensitive areas of the data centre.

The site is monitored so teams can detect and respond to issues quickly, whether that relates to access, power, cooling, equipment or fire safety.

What does it enable?

Security helps protect the infrastructure behind the digital services you rely on.

It also supports safe, reliable operation for the businesses and services using the data centre.

What do people typically ask?

Why does a data centre need so much security?

Data centres were legally designated as critical national infrastructure by the UK Government and support highly important digital systems.

The security is there to protect the equipment, maintain reliability and reduce the risk of disruption. It is also one of the reasons data centres are carefully designed and managed.

What is it?

Construction and site preparation cover the work needed before a data centre can open.

This can include surveys, demolition, groundworks, utility connections, power works, construction, testing and safety checks.

How does it work?

Every site is different.

Some sites need more preparation than others, especially if power connections, ground conditions or former industrial buildings need to be managed first.

A site can look quiet even when important work is happening behind the scenes.

What does it enable?

Good preparation helps make sure the data centre can operate safely, securely and reliably once it opens.

It also helps manage construction impacts such as traffic, noise and site access.

What do people typically ask?

Why does construction take so long?

A lot has to happen before a data centre is ready to work.

Some of the most important work happens before the building is visible, including planning, ground preparation and connections to power and connectivity networks.

Construction can be disruptive. The aim is to explain what is happening, why it is happening and how impacts are being managed.

People who keep it running

What is it?

Data centres are not empty buildings. They rely on skilled people to keep the site secure, safe and running properly every day.

This includes engineers, technicians, facilities teams, security staff and operational support.

How does it work?

People working in a data centre monitor systems, maintain equipment, check performance, respond to issues and help ensure everything operates safely and reliably.

Some roles are based on-site every day, while others visit as needed for maintenance, specialist checks or customer support.

What does it enable?

The people working in a data centre help make sure digital services stay available.

Their work supports:

• Safe day-to-day operations
• Reliable power and cooling
• Equipment maintenance
• Security and monitoring
• Fast response if something goes wrong
• Long-term performance of the site

What do people typically ask?

Do data centres actually create jobs?

Yes. Data centres create jobs during both construction and operation.

Once open, they can support roles in engineering, facilities management, security, operations and maintenance. They can also create work for local suppliers, specialist contractors and service partners.

The number of people on-site will vary depending on the size and type of facility, but data centres do employ people and depend on skilled teams to keep them running.