add info to merge page (#24972)

* add info to merge page

* Update merge.md

Co-authored-by: Felix Lange <fjl@twurst.com>

docs/_interface/merge.md

@@ -3,45 +3,53 @@ title: The Merge
 sort_key: A2
 ---
 
-As an Execution-Layer (EL) client, Geth supports the transition of Ethereum from PoW to
+As an Execution-Layer (EL) client, Geth supports the transition of Ethereum from proof-of-work (PoW) to
-PoS, a.k.a. [The Merge](https://ethereum.org/en/upgrades/merge/). As this milestone
+proof-of-stake (PoS), a.k.a. [The Merge](https://ethereum.org/en/upgrades/merge/). In advance of the Mainnet
-approaches for the Ropsten testnet, users running a Geth node will need to keep a few
+merge, several public testnets will transition from PoW to PoS. The first public testnet to merge will be 
-things in mind to ensure a smooth transition.
+Ropsten. As the Ropsten merge approaches, Geth users will need to prepare to ensure a smooth transition.
+
+### What happens to Geth?
+
+The merge swaps Ethereum's PoW consensus mechanism for a new PoS mechanism. At the moment of the merge, 
+Geth switches off its mining algorithm and block gossip functions. Geth's role after the merge is 
+to execute transactions, generate execution payloads and run the [EVM](https://ethereum.org/en/developers/docs/evm).
+
+From a user perspective Geth will not change much at the merge. Responsibility for consensus logic and
+block propagation are handed over to the consensus layer, but all of Geth's other functionality remains
+intact. This means transactions, contract deployments and data queries can still be handled by Geth using
+the same methods as before.
 
 ### Transition
 
-The transition will happen when a pre-announced total difficulty is reached by the chain.
+The transition from PoW to PoS will happen when a pre-announced total difficulty is reached by the chain. 
 This is unlike usual forks which occur at a certain scheduled block number.
 
-The total difficulty threshold that triggers the Merge is also known as the *Terminal
+The total difficulty threshold that triggers the Merge is also known as the [*Terminal
-Total Difficulty* (TTD).
+Total Difficulty* (TTD)](https://ethereum.org/en/glossary/#terminal-total-difficulty).
 
 {% include note.html content="In case of an emergency delay, the TTD can be overriden using `--override.totalterminaldifficulty`." %}
 
 ### Consensus client
 
-After the Merge, Ethereum's Proof-Of-Stake consensus logic is handled by a separate piece
+After the merge, Geth will no longer be able to follow the head of the chain unless it is connected to a second
-of software called a Consensus-Layer (CL) client.
+piece of software known as a ["consensus client"](https://ethereum.org/en/developers/docs/nodes-and-clients/#consensus-clients)
-
+which handles all of Ethereum's consensus logic. 
-This means running Geth alone will not suffice to be able to follow the chain. You must
-set up a consensus client and configure it so it can talk to Geth. This has to be done
-before the Merge event happens.
 
-The two clients will coordinate the transition together.
+The consensus client communicates with Geth using the `engine` API over a local RPC connection. The consensus client 
+is responsible for gossiping blocks, block proposal, attestation and fork choice. 
 
-You can choose one of several [Consensus Client implementations][cl-list].
+Geth must be connected to a consensus client in advance of the merge so that the two pieces of software can get in sync and
+transition smoothly by coordinating together. There are several choices of [consensus client implementations][cl-list].
 
-Note that CL clients are equipped with two modes. One for following the beacon chain
+Note that CL clients are equipped with two modes. One for following the beacon chain (Beacon node), and another mode 
-(beacon node), and another mode used for validators. **It is NOT required to run a
+used for validators. **It is NOT required to run a validator or stake 32 ETH in order to follow the chain!**
-validator or stake 32 ETH in order to follow the chain!**
 
 ### EL - CL communication
 
-ELs and CLs communicate using a [JSON-RPC API][engineapi] under the namespace `engine`
+ELs and CLs communicate using a [JSON-RPC API][engineapi] under the namespace `engine` which is exposed by Geth.
-which is exposed by Geth.
 
-The `engine` API is authenticated via [JWT](https://jwt.io). If a TTD is set for the given
+The `engine` API is authenticated via [JWT](https://jwt.io). If a TTD is set for the given network, as is the 
-network, as is the case for Ropsten, Geth will:
+case for Ropsten, Geth will:
 
 - Generate a JWT secret under the path `<datadir>/geth/jwtsecret`. This secret is needed
   both by Geth and the CL client.
@@ -65,18 +73,20 @@ INFO [05-25|11:04:41.628] HTTP server started                      endpoint=127.
 
 ### Engine API Authentication
 
-The listening address of the engine API is configurable. It is also possible to
+The listening address of the engine API is configurable. It is also possible to self-generate the JWT secret and feed the resulting file to Geth. To generate the secret, run:
-self-generate the JWT secret and feed the resulting file to Geth. To generate the secret,
-run:
 
 ```shell
+
 openssl rand -hex 32 | tr -d "\n" > "/tmp/jwtsecret"
+
 ```
 
 Now configure authentication using Geth flags:
 
 ```shell
+
 geth --ropsten --datadir ~/.ropsten --authrpc.addr localhost --authrpc.port 8551 --authrpc.vhosts localhost --authrpc.jwtsecret /tmp/jwtsecret
+
 ```
 
 [engineapi]: https://github.com/ethereum/execution-apis/blob/main/src/engine/specification.md