Several of these are used loosely across the niche in ways that obscure who is responsible for what.

How the thing is put together

Agent
A local intermediary who resells operator accounts. Adds a party between you and the licensed entity, and removes whatever protection the licence provided.
Client
The game lobby itself. It loads titles and accepts a login. It holds no money.
Operator
The company holding your account, your balance and your withdrawal decision. The only party in this chain you can meaningfully evaluate.
SCR888
The original name of the client before the rebrand to 918Kiss and Kiss918.

Installing and devices

APK
An Android package file. Because the client is not in the app stores, this is how it is distributed — and why provenance matters so much.
Configuration profile
The iOS equivalent of an APK for this category. Apple revokes them when found, which is why iOS installs stop working.
Unknown sources
The Android setting that permits installing outside the store. Worth switching off again immediately after use.

Money and offers

Free credit
Promotional balance, usually with wagering attached. Rarely withdrawable without meeting a turnover requirement first.
Game weighting
The share of each stake that counts toward a wagering requirement. Some titles count at a fraction, some at zero.
RTP
Return to player. For licensed studio games it is published and audited. For this client, no such figure exists in any verifiable form.
Wagering requirement
Turnover you must complete before a bonus or its winnings become withdrawable, expressed as a multiple.
Withdrawal cap
The maximum withdrawable from bonus play, regardless of balance. Often the term that decides whether an offer was worth taking.

Definition questions

What is the difference between an operator and an agent?

An operator holds the licence and the funds. An agent resells access and sits between you and that licence, which usually means less recourse rather than more.

Why does “unknown sources” matter?

It is the Android setting that permits installing outside the store. Leaving it on removes a safeguard for everything you install afterwards, not just this app.

What is free credit worth?

Whatever survives the wagering requirement and the withdrawal cap. Often less than the headline suggests.
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