## Privacy and Fungibility
There are 3 main properties of Grin transactions that make them private:
There are no addresses.
There are no amounts.
2 transactions, one spending the other, can be merged in a block to form only one, removing all intermediary information.
The 2 first properties mean that all transactions are indistinguishable from one another. Unless you directly participated in the transaction, all inputs and outputs look like random pieces of data (in lingo, they're all random curve points).
Moreover, there are no more transactions in a block. A Grin block looks just like one giant transaction and all original association between inputs and outputs is lost.
## Scalability
As explained in the previous section, thanks to the MimbleWimble transaction and block format we can merge transactions when an output is directly spent by the input of another. It's as if when Alice gives money to Bob, and then Bob gives it all to Carol, Bob was never involved and his transaction is actually never even seen on the blockchain.
Pushing that further, between blocks, most outputs end up being spent sooner or later by another input. So *all spent outputs can be safely removed*. And the whole blockchain can be stored, downloaded and fully verified in just a few gigabytes or less (assuming a number of transactions similar to bitcoin).
This means that the Grin blockchain scales with the number of users (unspent outputs), not the number of transactions. At the moment, there is one caveat to that: a small piece of data (called a *kernel*, about 100 bytes) needs to stay around for each transaction. But we're working on optimizing that as well.
## Scripting
Maybe you've heard that MimbleWimble doesn't support scripts. And in some way, that's true. But thanks to cryptographic trickery, many contracts that in Bitcoin would require a script can be achieved with Grin using properties of Elliptic Curve Cryptography. So far, we know how to do:
* Multi-signature transactions.
* Atomic swaps.
* Time-locked transactions and outputs.
* Lightning Network
## Emission Rate
Bitcoin's 10 minute block time has its initial 50 btc reward cut in half every 4 years until there are 21 million bitcoin in circulation. Grin's emission rate is linear, meaning it never drops. The block reward is currently set at 60 grin with a block goal of 60 seconds. This still works because 1) dilution trends toward zero and 2) a non-negligible amount of coins gets lost or destroyed every year.