Explain like I'm five · Cloud

What is Serverless Computing?

Serverless computing, told as a story about an hourly meeting room that opens only when you actually need it.

my office, empty almost all yeara whole office, just for a one-hour meeting?keeping a whole office for something you use rarely feels wasteful

Keeping a whole office for something you use rarely feels wasteful.Even though that office sits empty almost all year.

emptybut rent still goes out every montheven unused hours still rack up fixed cost

Even unused hours still rack up fixed cost.Isn't there a way to pay only for what's used?

hourly meeting roomopens only when usedserverless = an hourly meeting room that opens only when usedthe building handles all the "office" management for you

Serverless = an hourly meeting room that opens only when used.The building handles all the "office" management for you.

Pay only for the hours usedno run charges while unused
The building manages the "office"you only worry about the meeting itself (your code)
The room opens when a request arrivescalled event-driven
A closed room is a bit slow to open the first timecalled a cold start
always-on office vs hourly meeting roomcost: flat rent vs pay only for hours usedupkeep: you manage it vs the building handles itstandby: always on vs closed by defaultopening speed: instant vs a bit slow the first time

Always-on office and hourly meeting room differ on cost, upkeep, standby, and opening speed.For occasional work, the hourly room costs less than an always-on office.

opening a closed-down room takes a moment (cold start)all-day work still fits an always-on office better

An hourly room is a bit slow to open at first (cold start), and it's not great for long-running work.The hourly room (serverless) fits short, occasional work best.

In one breath

Serverless is an hourly meeting room whose door opens automatically only when used, and you pay only for the time used. The building handles all the "office" management for you.

It doesn't mean there's no server — it means the cloud provider manages it, so you never have to. Code runs only when triggered (event-driven, e.g. FaaS), and billing follows exact usage. When code that was shut down after a while without requests wakes up again, the delay is called a cold start.

When grown-ups say it

Serverless
The meeting room that opens only when used. It's not that there's no server — you just never manage one.
FaaS (Function as a Service)
Handing the room just one single task to run. When a request arrives, the function that handles it runs.
Event-driven
The door opens only when a request arrives. With no request, your code doesn't run.
Cold start
The time it takes to open a closed door for the first time. Frequently used functions are already awake, so this delay shrinks.
Pay-as-you-go
Paying only for the hours actually used. The opposite of an always-on office's flat rent.
VM / Container
The always-on private office or partitioned desk. A step heavier than serverless. → the private office and the partitioned desk
Auto scale
Automatically adding more meeting rooms. In serverless, the building adds rooms completely on its own. → bigger office or more offices
Edge computing
A small branch office close to the neighborhood. Serverless functions are sometimes placed at the edge too. → the small branch close to the neighborhood
Next story
The Local Branch, and the Hub In Between →
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