Promote and improve the glossary page (#6493)

doc/docusaurus/docs/essential-concepts/ledger.md

@@ -52,15 +52,15 @@ So a transaction that sends 5 USD from Alice to Bob would do so by spending some
 
 UTXO-based ledgers are more complicated, but avoid some of the issues of account-based ledgers, since any transaction deals only with the inputs that it spends.
 Cardano is a UTXO-based ledger, and we heavily rely on this.
-For example, [Hydra](../delve-deeper/glossary.md#hydra), Cardano's scalability solution, uses the fact that independent parts of the transaction graph can be processed in parallel to improve throughput.
+For example, Hydra, Cardano's scalability solution, uses the fact that independent parts of the transaction graph can be processed in parallel to improve throughput.
 
 ## Scripts and the Extended UTXO Model
 
 UTXO-based ledgers typically start out with a very simple model of "ownership" of UTXOs.
 An output will have a public key (strictly, the hash of a public key) attached to it, and in order to spend this output, the spending transaction must be signed by the corresponding private key.
 We call this a "pay-to-pubkey" output.
 
-Cardano uses an extended model called the [Extended UTXO Model](../delve-deeper/glossary.md#extended-utxo-model) (EUTXO).
+Cardano uses an extended model called the [Extended UTXO Model](../glossary.md#extended-utxo-model) (EUTXO).
 In the EUTXO model, an output can be locked by (the hash of) a *script*.
 We call this a "pay-to-script" output.
 A script is a *program* that decides whether or not the transaction which spends the output is

doc/docusaurus/docs/essential-concepts/plutus-platform.mdx

@@ -4,7 +4,7 @@ sidebar_position: 15
 
 # Plutus platform
 
-The Plutus platform is a platform for writing *applications* that interact with a *distributed ledger* featuring *scripting* capabilities, in particular the [Cardano](../delve-deeper/glossary.md#cardano) blockchain.
+The Plutus platform is a platform for writing *applications* that interact with a *distributed ledger* featuring *scripting* capabilities, in particular the [Cardano](../glossary.md#cardano) blockchain.
 
 ## Example application
 

doc/docusaurus/docs/glossary.md

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+---
+sidebar_position: 15
+---
+
+# Glossary
+
+### Address
+
+Each UTXO has an address, which stipulates the conditions for spending the UTXO.
+
+An address on Cardano can be based on either a public key hash, which requires a private key signature corresponding to the public key hash to spend the UTXO, or a script hash, which requires the script with that particular hash to be executed to spend the UTXO.
+These are referred to as public key address and script address, respectively.
+
+### Cardano
+
+The blockchain system for which Plutus Core and Plutus Tx are built.
+
+### Contract Blueprint
+
+A contract blueprint enables communication between on-chain code and off-chain code written in different languages.
+It is introduced in [CIP-57](https://developers.cardano.org/docs/governance/cardano-improvement-proposals/cip-0057/).
+Also see [Producing a Plutus Contract Blueprint](./working-with-scripts/producing-a-blueprint.md).
+
+### Currency Symbol and Token Name
+
+On Cardano, each class of tokens (or asset class) is identified by its currency symbol (also known as currency, or asset group) along with the token name.
+The minting and burning of a token are controlled by the Plutus script whose hash corresponds to the token's currency symbol.
+
+Ada/Lovelace is a special asset class where the currency symbol and token name are both empty strings, and it cannot be minted or burned via transactions.
+
+See [_UTXOma: UTXO with Multi-Asset Support_](https://iohk.io/en/research/library/papers/utxomautxo-with-multi-asset-support/).
+
+### Datum
+
+A piece of data attached to a UTXO at a script address.
+The datum serves as an input to the script, and is often used to represent the state of a smart contract.
+
+### Extended UTXO Model (EUTXO)
+
+An extended version of the UTXO model, where each UTXO can carry additional data (or "datum"), and be associated with a Plutus script that specifies the conditions under which the UTXO can be spent.
+See [_The Extended UTXO Model_](https://iohk.io/en/research/library/papers/the-extended-utxo-model/).
+
+### Guardrail Script
+
+A guardrail script, sometimes referred to as a consitution script or a proposing script, is a Plutus V3 script used to validate two kinds of governance actions: parameter change and treasury withdrawal.
+See [Script Purposes](./working-with-scripts/script-purposes.md).
+
+### Hard Fork
+
+A hard fork is an update of the major protocol version, i.e., transitioning the protocol version from `x.y` to `x+1.0`.
+A hard fork is required when a backwards incompatible change to the Cardano node is made, causing the old node to reject some blocks produced by the new node.
+As a result, old nodes are no longer able to validate the chain, and all participants must upgrade to the new version.
+A hard fork is initiated by a transaction that updates the protocol version.
+The protocoal version is one of the protocol parameters, and like other protocol parameter changes, a hard fork always takes effect at an epoch boundary.
+
+A hard fork may or may not introduce a new ledger era.
+The latter is called an intra-era hard fork.
+For example, the Vasil hard fork introduced the Babbage era, and the Chang hard fork introduced the Conway era.
+The Valentine hard fork is an example of an intra-era hard fork.
+
+### Ledger Era
+
+A ledger era marks a specific period where new features are added to the Cardano ledger, for instance
+
+- The Alonzo era, which followed the Alonzo hard fork, introduced smart contracts and Plutus V1.
+- The Babbage era, which followed the Vasil hard fork, introduced Plutus V2 along with features such as reference scripts and inline datum.
+- The Conway era, which followed the Chang hard fork, introduced Plutus V3 and features such as governance actions and voting.
+
+A hard fork is required to introduce a new ledger era, but a hard fork does not necessarily introduce a new ledger era.
+
+### Ledger Language Version
+
+This is what "Plutus V1", "Plutus V2", "Plutus V3" refer to.
+See [Different Notions of Version](./essential-concepts/versions) and [Plutus Ledger Language Version](./working-with-scripts/ledger-language-version).
+
+### Minting Policy Script
+
+A Plutus script which must be satisfied in order for a transaction to mint tokens of the corresponding currency.
+
+### Off-chain Code
+
+Code executed by individual applications rather than Cardano nodes.
+This includes functions like building, signing, and submitting transactions.
+Off-chain code can be developed using libraries like [Mesh](https://meshjs.dev/), [PyCardano](https://pycardano.readthedocs.io/en/latest/) and [Cardano API](https://github.com/IntersectMBO/cardano-api).
+
+### On-chain Code
+
+Code executed directly on the Cardano blockchain by each participating node.
+The main function of on-chain code is for nodes to validate transactions, such as checking if a transaction is permitted to spend a UTXO or mint a token.
+On-chain code is usually written in a high level language like Plutus Tx, and compiled into Untyped Plutus Core (UPLC).
+The Cardano node includes an evaluator that runs UPLC programs.
+
+### The Plugin
+
+The compiler from Plutus Tx to Untyped Plutus Core, which is implemented as a GHC plugin.
+
+### Plutus
+
+The term "Plutus" can refer to Untyped Plutus Core, Typed Plutus Core, or, prior to its renaming to Plinth, Plutus Tx.
+To avoid ambiguity, it is advisable not to use "Plutus" on its own.
+
+### Plutus Core
+
+The term "Plutus Core" can refer either to Untyped Plutus Core or Typed Plutus Core, depending on the context.
+To avoid confusion, it is recommended to use UPLC for Untyped Plutus Core and TPLC for Typed Plutus Core.
+
+### Plutus IR
+
+An intermediate language that compiles to Plutus Core.
+See [Plutus Core and Plutus Tx](./essential-concepts/plutus-core-and-plutus-tx.md).
+
+### Plutus Metatheory
+
+The formalization of typed and untyped Plutus Core.
+In the future we may add Plutus IR to the formalization.
+It is "meta" in the sense that it is a framework for reasoning about the Plutus Core languages themselves.
+
+### Plutus Script/Validator
+
+A Plutus script, or Plutus validator, is a UPLC program executed on-chain.
+Sometimes a program written in a high level language that compiles to UPLC, such as Plutus Tx, is also referred to as a Plutus script.
+
+### Plutus Tx
+
+Plutus Tx is a high-level language for writing the validation logic of transactions. See [Plutus Core and Plutus Tx](./essential-concepts/plutus-core-and-plutus-tx.md).
+
+### Protocol Parameters
+
+Various settings that control the behavior of the Cardano blockchain.
+
+### Protocol Version
+
+A key protocol parameter that indicates the current version of the blockchain protocol in use.
+It is in the form of `x.y`, where `x` is the major protocol version and `y` is the minor protocol version.
+A hard fork bumps the major protocol version, while a soft fork bumps the minor protocol version.
+
+Protocol versions are closely tied to Cardano node versions.
+A node of major version `x` supports up to major protocol version `x`.
+Thus after a hard fork that bumps the major protocol version to `x+1`, node version `x` or older will become obsolete, requiring all participants to upgrade their nodes.
+
+### Redeemer
+
+A piece of data included in a transaction that serves as an input to a Plutus script that needs to be executed to validate this transaction.
+
+If a smart contract is regarded as a state machine, the redeemer would be the input that ticks the state machine.
+
+### Script Context
+
+An input to a Plutus script created by the ledger.
+It includes details of the transaction being validated.
+Additionally, since a transaction may do multiple things, each of which needs to be validated by a separate script, the script context also specifies what exactly the current script is responsible for validating.
+
+### Typed Plutus Core
+
+The typed counterpart of Untyped Plutus Core, and can serve as a low-level IR for compilers targeting Untyped Plutus Core.
+See [Plutus Core and Plutus Tx](./essential-concepts/plutus-core-and-plutus-tx.md).
+
+### Untyped Plutus Core
+
+A low-level language for on-chain code, based on untyped lambda calculus, a well-studied formalism for computing.
+See [Plutus Core and Plutus Tx](./essential-concepts/plutus-core-and-plutus-tx.md).
+
+### UTXO
+
+UTXO stands for unspent transaction output.
+Cardano adopts the UTXO model, one of the two popular ledger models for blockchains, the other one being the account model.