[docs] Adding content pages under "developing" section

docs/sidebars.js

@@ -81,6 +81,11 @@ module.exports = {
       id: "developing/programming-model/overview",
       label: "Overview",
     },
+    {
+      type: "category",
+      label: "Getting Started",
+      items: ["developing/intro/programs", "developing/intro/rent"],
+    },
     {
       type: "category",
       label: "Core Concepts",

docs/src/developing/intro/programs.md

@@ -0,0 +1,57 @@
+---
+title: What are Solana Programs?
+description: "A Solana Program, aka smart contract, is the executable code that interprets the instructions on the blockchain. There are two types: Native and on chain."
+keywords: ""
+---
+
+Solana Programs, often referred to as "_smart contracts_" on other blockchains, are the executable code that interprets the instructions sent inside of each transaction on the blockchain. They can be deployed directly into the core of the network as [Native Programs](#native-programs), or published by anyone as [On Chain Programs](#on-chain-programs). Programs are the core building blocks of the network and handle everything from sending tokens between wallets, to accepting votes of a DAOs, to tracking ownership of NFTs.
+
+Both types of programs run on top of the [Sealevel runtime](https://medium.com/solana-labs/sealevel-parallel-processing-thousands-of-smart-contracts-d814b378192), which is Solana's _parallel processing_ model that helps to enable the high transactions speeds of the blockchain.
+
+## Key points
+
+- Programs are essentially special type of [Accounts](../programming-model/accounts.md) that is marked as "_executable_"
+- Programs can own other Accounts
+- Programs can only _change the data_ or _debit_ accounts they own
+- Any program can _read_ or _credit_ another account
+- Programs are considered stateless since the primary data stored in a program account is the compiled BPF code
+- Programs can be upgraded by their owner (see more on that below)
+
+## Types of programs
+
+The Solana blockchain has two types of programs:
+
+- Native programs
+- On chain programs
+
+### On chain programs
+
+These user written programs, often referred to as "_smart contracts_" on other blockchains, are deployed directly to the blockchain for anyone to interact with and execute. Hence the name "on chain"!
+
+In effect, "on chain programs" are any program that is not baked directly into the Solana cluster's core code (like the native programs discussed below).
+
+And even though Solana Labs maintains a small subset of these on chain programs (collectively known as the [Solana Program Library](https://spl.solana.com/)), anyone can create or publish one. On chain programs can also be updated directly on the blockchain by the respective program's Account owner.
+
+### Native programs
+
+_Native programs_ are programs that are built directly into the core of the Solana blockchain.
+
+Similar to other "on chain" programs in Solana, native programs can be called by any other program/user. However, they can only be upgraded as part of the core blockchain and cluster updates. These native program upgrades are controlled via the releases to the [different clusters](../../cluster/overview.md).
+
+#### Examples of native programs include:
+
+- [System Program](../runtime-facilities/programs.md#system-program): Create new accounts, transfer tokens, and more
+- [BPF Loader Program](../runtime-facilities/programs.md#bpf-loader): Deploys, upgrades, and executes programs on chain
+- [Vote program](../runtime-facilities/programs.md#vote-program): Create and manage accounts that track validator voting state and rewards.
+
+## Executable
+
+When a Solana program is deployed onto the network, it is marked as "executable" by the [BPF Loader Program](../runtime-facilities/programs.md#bpf-loader). This allows the Solana runtime to efficiently and properly execute the compiled program code.
+
+## Upgradable
+
+Unlike other blockchains, Solana programs can be upgraded after they are deployed to the network.
+
+Native programs can only be upgraded as part of cluster updates when new software releases are made.
+
+On chain programs can be upgraded by the account that is marked as the "_Upgrade Authority_", which is usually the Solana account/address that deployed the program to begin with.

docs/src/developing/intro/rent.md

@@ -0,0 +1,40 @@
+---
+title: What is rent?
+description: "Rent: the small fee Solana accounts incur to store data on the blockchain. Accounts with >2 years of rent are rent exempt and do not pay the periodic fee."
+keywords: ""
+---
+
+The fee every Solana Account to store data on the blockchain is called "_rent_". This _time and space_ based fee is required to keep an account, and its therefore its data, alive on the blockchain since [clusters](../../cluster/overview.md) must actively maintain this data.
+
+All Solana Accounts (and therefore Programs) are required to maintain a high enough LAMPORT balance to become [rent exempt](#rent-exempt) and remain on the Solana blockchain.
+
+When an Account no longer has enough LAMPORTS to pay its rent, it will be removed from the network in a process known as [Garbage Collection](#garbage-collection).
+
+> **Note:** Rent is different from [transactions fees](../../transaction_fees.md). Rent is paid (or held in an Account) to keep data stored on the Solana blockchain. Where as transaction fees are paid to process [instructions](../developing/../programming-model/transactions.md#instructions) on the network.
+
+### Rent rate
+
+The Solana rent rate is set on a network wide basis, primarily based on the set LAMPORTS _per_ byte _per_ year.
+
+Currently, the rent rate is a static amount and stored in the the [Rent sysvar](../runtime-facilities/sysvars.md#rent).
+
+## Rent exempt
+
+Accounts that maintain a minimum LAMPORT balance greater than 2 years worth of rent payments are considered "_rent exempt_" and will not incur a rent collection.
+
+> At the time of writing this, new Accounts and Programs **are required** to be initialized with enough LAMPORTS to become rent-exempt. The RPC endpoints have the ability to calculate this [estimated rent exempt balance](../clients/jsonrpc-api.md#getminimumbalanceforrentexemption) and is recommended to be used.
+
+Every time an account's balance is reduced, a check is performed to see if the account is still rent exempt. Transactions that would cause an account's balance to drop below the rent exempt threshold will fail.
+
+## Garbage collection
+
+Accounts that do not maintain their rent exempt status, or have a balance high enough to pay rent, are removed from the network in a process known as _garbage collection_. This process is done to help reduce the network wide storage of no longer used/maintained data.
+
+You can learn more about [garbage collection here](../../implemented-proposals/persistent-account-storage.md#garbage-collection) in this implemented proposal.
+
+## Learn more about Rent
+
+You can learn more about Solana Rent with the following articles and documentation:
+
+- [Implemented Proposals - Rent](../../implemented-proposals/rent.md)
+- [Implemented Proposals - Account Storage](../../implemented-proposals/persistent-account-storage.md)

docs/src/terminology.md

@@ -205,7 +205,7 @@ The private key of a [keypair](#keypair).
 
 ## program
 
-The code that interprets [instructions](#instruction).
+The executable code that interprets the [instructions](#instruction) sent inside of each [transaction](#transaction) on the Solana. These programs are often referred to as "[_smart contracts_](./developing//intro/programs.md)" on other blockchains.
 
 ## program derived account (PDA)
 
@@ -231,6 +231,16 @@ Transactions should request the minimum amount of compute units required for exe
 
 The public key of a [keypair](#keypair).
 
+## rent
+
+Fee paid by [Accounts](#account) and [Programs](#program) to store data on the blockchain. When accounts do not have enough balance to pay rent, they may be Garbage Collected.
+
+See also [rent exempt](#rent-exempt) below. Learn more about rent here: [What is rent?](../src/developing/intro/rent.md).
+
+## rent exempt
+
+Accounts that maintain more than 2 years with of rent payments in their account are considered "*rent exempt*" and will not incur the [collection of rent](../src/developing/intro/rent.md#collecting-rent).
+
 ## root
 
 A [block](#block) or [slot](#slot) that has reached maximum [lockout](#lockout) on a [validator](#validator). The root is the highest block that is an ancestor of all active forks on a validator. All ancestor blocks of a root are also transitively a root. Blocks that are not an ancestor and not a descendant of the root are excluded from consideration for consensus and can be discarded.