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Lesson 2 of 9 · about 16 minutes

The Types of Data Centers, Side by Side

You'll be able to

  • Name the main types of data center and what each is for
  • Estimate a facility's type from its megawatts, square footage and owner
  • Explain the difference between AI training and AI inference facilities
  • Explain what a cloud region and an availability zone are

"Data center" covers everything from a locked closet behind a dentist's front desk to a campus that wants a gigawatt. Anyone who uses one word for all of it ends up comparing a corner store to a regional distribution warehouse. The useful questions are who owns it, who uses it, what work it does, and how much power it draws. Those four answers sort almost every facility into one of the types below.

The big comparison table

Sizes in this table are typical ranges drawn from the named examples and industry reporting. They are rules of thumb. No standards body defines "hyperscale" by megawatts. Treat the edges of each range as soft.

TypeWhat it doesTypical IT powerTypical floor areaUsual ownerExamples (as of October 2026)
On-premises enterpriseRuns one organization's own systems: payroll, records, phones, filesUnder 0.1 MW to about 5 MWA room to about 50,000 sq ftThe organization itself: a bank, hospital, university, state agencyA county government server room; a hospital system's main data center
Retail colocationRents racks, cages or small suites to many tenants; often hosts internet exchangesAbout 1 to 30 MW per buildingAbout 20,000 to 300,000 sq ftColocation companies, many organized as REITsEquinix lists 282 data centers in 70-plus metros
Wholesale colocationLeases whole halls or buildings to one large tenantAbout 10 to 100+ MW per buildingAbout 100,000 to 500,000+ sq ftDevelopers and REITs, often backed by private equityDigital Realty lists 300-plus data centers in 55-plus metros
Hyperscale (self-built)Runs a giant company's own services and cloudTens to hundreds of MW per campusHundreds of thousands to millions of sq ftAmazon, Microsoft, Google, Meta, Apple, Oracle and a few othersSynergy Research counted 1,136 hyperscale facilities at the end of 2024 (published March 2025)
Cloud region and availability zonesA cluster of hyperscale buildings arranged for fault isolationEach AZ is one or more buildings; regions reach hundreds of MW or moreSpread over several sitesCloud providersAWS: 124 AZs in 39 Regions
EdgeSmall sites close to users or devices for low delay or local cachingA few kW to about 5 MWA cabinet to about 10,000 sq ftTelecom carriers, CDNs, tower companiesCache servers at a carrier hub; a micro site at a cell tower
AI training clusterTens or hundreds of thousands of tightly linked GPUs building models100 MW to over 1 GW per campusAbout 1 to 4+ million sq ft per campusHyperscalers, AI labs, and partners such as Oracle and CrusoeStargate Abilene, Texas: 1.2 GW planned, about 4 million sq ft; Microsoft Fairwater, Wisconsin: 1.2 million sq ft on 315 acres
AI inferenceAnswers live AI requests from users and appsTens to hundreds of MW, often inside cloud regionsVariesCloud providers, AI companiesUsually hosted in existing cloud regions near population centers
High-performance computing (HPC)Scientific simulation, weather, weapons and energy researchAbout 1 to 40 MW per systemUsually one large machine roomNational labs, universities, governmentsFrontier at Oak Ridge, about 24.6 MW; El Capitan at Livermore, about 29.7 MW
Crypto miningRuns specialized machines that compete to validate blockchain transactionsTens to hundreds of MWOften simple metal sheds or containers on large acreagePublicly traded miners and private operatorsRiot Platforms, Rockdale, Texas: 700 MW
Modular or containerizedFactory-built power, cooling or IT modules shipped and set on a padA few hundred kW to a few MW per moduleShipping-container to small-building sizeAnyone needing speed: miners, militaries, remote sites, AI startupsModules stacked at oil fields, mines or temporary sites

Enterprise, colocation and the slow move out of the basement

For decades most companies ran their own server rooms. That is changing. Uptime Institute's 2026 survey summary says that, for the first time, third-party facilities and services host a larger share of IT workloads than enterprise-owned data centers (counted by facility, not total capacity). A hospital may keep a small room on site for systems that must work even if the internet link fails, then rent space at a colocation building and buy cloud services for the rest.

Colocation splits into two businesses. Retail colocation is like an apartment building: lots of tenants, each with a few racks or a caged area, sharing power and cooling. These buildings are where networks meet, so they tend to sit in big metros. Wholesale colocation is like leasing a whole warehouse: one tenant, often a hyperscaler, takes 10, 30 or 100 MW at a time on a long lease. When a developer you have never heard of files plans for a 300 MW campus, it is usually a wholesale play with a big tenant behind it.

Cloud regions and availability zones

Cloud providers group buildings so that one fire, flood or power failure does not take down a whole service. AWS calls the group a Region and the separate pieces Availability Zones. As of October 2026 it describes an AZ as one or more discrete data centers with redundant power, networking and connectivity, says each Region has at least three AZs, and says AZs are physically separated by a meaningful distance while staying within 100 km of each other. Microsoft and Google use similar terms. For anyone watching a local project, this explains why a cloud company might buy three parcels several miles apart instead of one big one.

Region (all zones within about 100 km) Zone AZone BZone C own substationown substationown substation own coolingown coolingown cooling redundant fiber between zones
Zones are close enough for fast data copying and far enough apart that one local disaster should hit only one of them.

AI training versus inference

These two jobs use similar chips and very different buildings. Training builds a model by running enormous numbers of calculations across tens or hundreds of thousands of GPUs that must talk to each other constantly. The GPUs need to sit close together on very fast links, so training wants one giant campus with a huge, steady power supply. It does not care much where that campus is, because it barely talks to users.

Inference is the model at work: answering a chat, summarizing a document, generating an image. Each request is small, but there are billions of them, and users notice delay. Inference tends to live inside existing cloud regions near people and fiber. As AI products spread, a larger share of AI electricity goes to inference, which may push more AI capacity back toward metro areas.

HPC, crypto mining and modular sites

Supercomputers at national labs are the ancestors of AI clusters. Frontier at Oak Ridge National Laboratory drew about 24.6 MW in the June 2026 TOP500 list, and El Capitan at Lawrence Livermore about 29.7 MW. Those are single machines in purpose-built rooms. A modern AI training campus can draw 40 times as much.

Crypto mining sites look like data centers from the road but behave differently. The machines do one task, need little network connection, and can shut off in minutes. EIA's preliminary estimate, published in February 2024, put U.S. bitcoin mining at 0.6 to 2.3 percent of U.S. electricity in 2023. Miners often sign deals to curtail during grid emergencies and get paid for it. Several mining companies have converted sites to AI hosting since 2024, because they already hold what AI builders want most: an energized grid connection.

Modular or containerized data centers are built in a factory as boxes of power gear, cooling or racks, then trucked to a site. They trade some efficiency and flexibility for speed. You see them at remote energy sites, military bases and temporary deployments, and as add-ons at bigger campuses.

Worked example: guess the type from a filing

The invented town of Harlow Flats gets a rezoning request from "Quartz Ridge Holdings LLC" for 640 acres. The application lists four buildings of 450,000 sq ft each and a utility service request of 900 MW.

  • Total floor area: 4 times 450,000 = 1,800,000 sq ft
  • Power per square foot: 900,000,000 W divided by 1,800,000 sq ft = 500 W per sq ft
  • Compare: an ordinary office uses a few watts per square foot.

Five hundred watts per square foot across the whole building area, plus 900 MW total, rules out enterprise, retail colocation, edge and HPC. It fits a hyperscale or AI campus. The LLC name tells you nothing yet; the next step is to find the tenant (lesson 3).

Common mix-ups

  • Claim: A crypto mine and an AI data center are the same thing. What the evidence shows: Both draw lots of power, but AI clusters need dense networking, liquid cooling and redundancy that most mining sheds lack. Converting a mine to AI usually means building new halls on the same power connection.
  • Claim: Square footage tells you how big a data center is. What the evidence shows: Megawatts matter more. An older 200,000 sq ft enterprise building may draw 10 MW; a new AI hall of the same size can draw ten times that.

Reporting angle

Ask every developer two numbers: total IT load in megawatts at full build-out and total utility service requested. The second is larger because it includes cooling and losses. Ask whether the project is self-built, wholesale lease or retail colocation, and whether it is for training, inference, cloud or mining. A mining site and an AI campus have very different job counts, noise profiles and tax value per megawatt, even at the same power level.

Research angle

Check yourself

1. A developer builds a large shell, then leases whole halls of 10 MW or more to one big tenant at a time. What type is that?

2. How does AWS describe an Availability Zone, as of October 2026?

3. Which type is most willing to switch off quickly when power prices spike?

4. Why does AI inference tend to sit closer to users than AI training?

5. The Frontier supercomputer at Oak Ridge drew about how much power in its June 2026 TOP500 listing?

6. A county sees a filing for a 1,000 MW campus of several 500,000 square foot buildings, owned by a large tech company. What type is it most likely to be?

Terms in this lesson

Colocation
A data center where the operator provides space, power, cooling and connectivity, and customers bring their own servers.
Hyperscale
Very large data centers, usually tens to hundreds of megawatts, built and run by the biggest cloud and internet companies.
Cloud region
A geographic area where a cloud provider clusters data centers, usually split into separate availability zones.
Edge data center
A small facility placed close to users or devices to cut delay, often under a few megawatts.
AI training
The long, compute-heavy job of building an AI model from data, usually inside one large GPU cluster.
AI inference
Running a trained model to answer requests, such as chat replies or image generation.

Full glossary

Sources