Update and rename docs/13-smart-contracts/01-plutus/06-collateral-mec…

…hanism.mdx to docs/03-learn/17-collateral-mechanism.mdx

docs/13-smart-contracts/01-plutus/06-collateral-mechanism.mdx → docs/03-learn/17-collateral-mechanism.mdx

@@ -1,28 +1,27 @@
 ---
 title: About the collateral mechanism
 metaTitle: About the collateral mechanism
-sidebar_position: 6
 ---
 
 The collateral mechanism is an important feature that has been designed to
 ensure successful smart contract execution.
 
 Relying on the guarantees provided by the deterministic design of the ledger,
 Cardano implements a two-phase validation scheme. The main reason for
-introducing two-phase validation is to limit the amount of uncompensated
+two-phase validation is to limit the amount of uncompensated
 validation work by nodes. Each phase serves a purpose in achieving this goal:
 
 - The first phase checks whether the transaction is constructed correctly and
   can pay its processing fee
-- The second phase runs the scripts included in the transaction
+- The second phase runs the scripts included in the transaction.
 
 If the transaction is _phase-1 valid_, phase-2 scripts run. If phase-1 fails, no
 scripts run, and the transaction is immediately discarded.
 
 Collateral is used to guarantee that nodes are compensated for their work in
 case phase-2 validation fails. Thus, collateral is the monetary guarantee a user
 gives to assure that the contract has been carefully designed and thoroughly
-tested. Collateral amount is specified at the time of constructing the
+tested. The collateral amount is specified at the time of constructing the
 transaction. Not directly, but by adding collateral inputs to the transaction.
 The total balance in the UTXOs corresponding to these specially marked inputs is
 the transaction’s collateral amount. If the user fulfills the conditions of the
@@ -39,7 +38,7 @@ users at little cost.
 ## The solution
 
 When a user initiates a transaction, they commit enough ada to cover its
-execution cost. In Alonzo, transactions that call and use non-native smart
+execution cost. On Cardano, transactions that call and use non-native smart
 contracts (known as phase-2 contracts) also need enough collateral to cover
 costs related to potential transaction failures. This amount can be small, but
 it is sufficient to make a denial of service (DOS) attack prohibitively
@@ -60,11 +59,10 @@ transaction before submitting it. This feature is different from other
 blockchains, including Ethereum, where other network activity can influence the
 gas cost. The required amount of collateral depends only on the execution cost.
 
-The
-[Cardano testnet](https://testnets.cardano.org/en/testnets/cardano/overview/)
-provides a safe environment with free test ada, so distributed application
-(DApp) developers can thoroughly test their smart contracts before deploying to
-the mainnet. If transactions succeed on the testnet, the developer can be
+The Cardano testnet
+provides a safe environment with free test ada, so decentralized application
+(DApp) developers can thoroughly test their smart contracts before deploying them to
+mainnet. If transactions succeed on testnet, the developer can be
 perfectly sure that all the scripts will indeed succeed.
 
 If the on-chain conditions have changed since the transaction was constructed,
@@ -77,22 +75,21 @@ The term collateral refers to the total ada contained in the UTXOs referenced by
 collateral inputs. A transaction uses collateral inputs to cover its fees if a
 phase-2 script fails.
 
-The Shelley formal specification introduced the concept of “multi-signature”
+The Shelley formal specification introduced the concept of 'multi-signature'
 scripts. Phase-1 scripts, such as these, are captured entirely by the ledger
 rules. Execution costs can therefore be easily assessed before they are
 processed by the implementation, and any fees can be calculated directly within
 the ledger rule implementation, based on the size of the transaction that
 includes the script, for example.
 
 In contrast, phase-2 scripts can perform arbitrary (and, in principle,
-Turing-complete) computations. We require transactions that use phase-2 scripts
+Turing-complete) computations. Cardano requires transactions that use phase-2 scripts
 to have a budget in terms of a number of abstract ExUnits. This budget gives a
 quantitative bound on resource usage in terms of a number of specific metrics,
 including memory usage or abstract execution steps. The budget is then used as
-part of the transaction fee calculation. For more details, read the
-[Cardano ledger specification for Plutus Core](https://www.google.com/url?q=https://hydra.iohk.io/build/7172824/download/1/alonzo-changes.pdf&sa=D&source=editors&ust=1631287783465000&usg=AOvVaw09WTwSfKshbLCGW7dyup62).
+part of the transaction fee calculation. 
 
-With the Vasil upgrade, DApp developers also have the possibility to specify a
+After the Vasil upgrade, DApp developers can also specify a
 change address for the script collateral. This means that in case the script
 fails phase-2 validation, only the right amount will be taken, and the remaining
 funds will be sent to the provided change address. The