Your First 90 DaysAcademy
Act I · The Space · Week 4 · Checkpoint 7

The Actual Players

By the end you will hold the org chart of this whole city: who the major players are, what each one actually does, and how a single dollar travels through all of them.

10 steps~24 min3 nodes for your map
01 · Names without a chart

By now you have heard the names dropped everywhere. Ethereum. Uniswap. Coinbase. Chainlink. They land like a foreign phone book: real, important, and impossible to keep straight.

This stop is the one nobody else teaches. We pin every major player to a wall in one map, sorted by the job it does. When you leave, the names stop being noise and become an address book you can actually use.

02 · The land: chains

Everything in this city is built ON something, and the something is a chain. A chain is the ground: the shared, ownerless ledger an app stands on. Two big grounds host most of the building you will meet: Ethereum and Solana. A third, Bitcoin, sits apart as the original money, less a construction site than a vault.

Tap each piece of land on the board. You are not memorizing them. You are learning that they are separate, because that one fact explains a lot of confusion later.

0 of 3 grounds surveyed
03 · The districts upgraded

Ethereum's ground got crowded, and crowded means expensive. So builders added upper floors that handle the same kind of work for much less. These extra layers built on top of a chain are called layer twos, or L2s. Arbitrum and Base are two of the busiest.

You do not need the machinery yet, that comes later in the tour. For the map, hold one picture: an L2 is a new floor on Ethereum's land, not a separate piece of ground. It belongs to the same plot.

04 · The businesses: protocols

Now the shops open on the land. These are protocols: businesses that are pure software, with no head office and no clerk behind a counter. You already met the trades in earlier stops. Here you finally get the storefront names.

A place to swap one token for another. A market to lend and borrow. A service to stake and earn the network wage. A marketplace for digital ownership. Tap each business on the board to put a name to the job.

0 of 4 businesses opened
05 · The utilities: infrastructure

A city runs on pipes and wires nobody admires. Same here. These are the utilities: the infrastructure that the shops quietly depend on, even though you rarely look at it directly.

Something to carry real-world prices onto the chain. Something to hold your keys and let you knock on any shop's door. Something to look up what actually happened. Tap each utility on the board to see what it carries.

0 of 3 utilities switched on
06 · The mints: stablecoin issuers

Remember the digital dollars from earlier, the stablecoins. Someone has to issue them, and that someone is the mint. A stablecoin issuer is a real company, with bank accounts and published reserve reports, that takes in dollars and hands out matching tokens that move on-chain.

Two mints carry most of this. The issuer behind the USDC token is the company Circle. The issuer behind the USDT token is the company Tether. They are the bridge between ordinary dollars and the chains, and unlike the shops, they are companies with names and addresses.

07 · The border crossings

Last piece. To get into this city at all, your dollars have to cross a border. The crossing point is a centralized exchange, or CEX: a regulated company where ordinary money enters and exits the chains. Coinbase, Binance, and Kraken are three of the biggest gates.

One honest reminder from the custody stop earlier. At a border crossing, the company holds your funds at its own table while they are there. It is convenient and it is custodial: the same trade-off you have already met. The map is now whole.

08 · The dollar's journey

Here is why the map matters. Follow a single dollar through the city and every player you pinned does exactly one job. The dollar leaves your bank card, crosses a border, becomes a digital dollar, lands in your wallet, gets swapped, gets lent, and stays watchable the whole way.

Walk the journey below. For each step, name the player. The address book you just built is about to do real work.

Scenario
You move one dollar through the city: card in, USDC in your wallet, a swap, a deposit to earn, a public check. Which lineup handles it, in order?
09 · Where the purity test breaks

You will hear it constantly online: a centralized company is not real crypto, the only true players are the ownerless ones. It sounds principled. Walk it against the map before you adopt it.

Limit test
Someone insists: "Coinbase is a centralized company, so it is not really part of crypto." Where does that break?
10 · The chart you keep

You can leave this stop with the whole org chart in your head. The land is the chains. The shops are the protocols. The utilities are the infrastructure. The mints issue the dollars. The gates are the border crossings.

From now on, when a name flies past, you have a wall to pin it to. Ask one question: what job does this player do, and which layer does it sit on. That habit turns the phone book into a map.

Last stop of the tour: the locals. How this city talks, jokes, hires, and occasionally loses its mind together. Next: The Culture.

your balance2,400
BANK_DBowner: the bank
you2,400
what the app is actually showing you
BANK_DBowner: the bank
you2,400their pen
you hold a claim. they hold the pen.
your digital life
BANK · you2,400the bank ✍
INSTAGRAM · you2.1M followersMeta ✍
STEAM · you134 gamesValve ✍
AIRLINE · you58,200 milesthe airline ✍
four tables. zero pens that are yours.
BANK_DBowner: the bank
you2,400
DENIED
try both pens
PLATFORM_DBowner: the platform
her · 8 years2,000,000 followers
one automated decision away
BANK_DB · you · 2,400intentcompetencecontinuity
your row stands on all three
FTX_DBowner: FTX
you5 BTC
the backing vault●●●●●
the row stayed. the backing did not.
CARD_DBowner: your bank ✍
TV you never bought−1,100
fraud reversal+1,100
someone holds the pen, so someone can fix it
?_DBowner: nobody
youstill yours?
?
can a table exist that nobody owns?
?
?_DBowner: ̶n̶o̶b̶o̶d̶y̶
you100
no owner, no pen, no trust?
keeper 1
you100
keeper 2
you100
keeper 3
you100
keeper 4
you100
keeper 5
you100
no THE copy, only copies.
keeper 2
you100
keeper 3
you100
keeper 4
you100
keeper 5
you100
your copy
you100
five copies. one of them is yours.
one attacker
one attacker, ten thousand faces.
real machinesburned wattsnext page, sealed
writing costs watts. faking voters buys nothing.
cost paid OUTSIDE: hardware and power
proof of work, burn energy to vote.
page 1you · 100page 2you · 100page 3you · 100page 4you · 100
rewrite one line, break every lock after it.
office lunchtrusted keeperconsensusfive keepers, real cost
the price buys trustlessness. the office already has trust.
?
ownerless ledger
you?
a key, not a login?
nobody owns the table. so who owns your row?
ethereumsolanainfrastructure

Three new nodes on your map

ethereum · solana · infrastructure · +10 Lynx