diff --git a/book/src/programs.md b/book/src/programs.md
index 666a2c55ce..da06cc59e2 100644
--- a/book/src/programs.md
+++ b/book/src/programs.md
@@ -1,12 +1,12 @@
 # Programming Model
 
-The Solana *runtime* can execute untrusted on-chain programs written in any
-programming language that can target the Berkley Packet Filter (BPF) safe
-execution environment. The Solana SDK offers the best support for C programs,
-which is compiled to BPF using the [LLVM compiler
-infrastructure](https://llvm.org). Alternatively, a client might choose to
-bypass LLVM and use Python, Lua or C++ to generate BPF directly via the [BPF
-Compiler Collection](https://github.com/iovisor/bcc) (BCC).
+A client interacts with a Solana cluster by sending it *transactions* with one
+or more *instructions*. The Solana *runtime* passes those instructions to
+user-contributed *programs*. An instruction might, for example, tell a program
+to move *tokens* from one *account* to another or create an interactive
+contract that governs how tokens are moved. Instructions are executed
+atomically. If any instruction is invalid, any changes made within the
+transaction are discarded.
 
 ## Deploying Programs to a Cluster
 
@@ -18,13 +18,12 @@ The cluster stores the program locally and makes it available to clients via a
 *program ID*. The program ID is a *public key* generated by the client and is
 used to reference the program in subsequent transactions.
 
-## Interacting with On-chain Programs
-
-After a program has been deployed, a client utilizes it by sending transactions
-to the Solana cluster. A transaction contains one or more *instructions*. Each
-instruction references the program ID that corresponds to the program that the
-runtime should use to execute it. Instructions are executed atomically. If any
-instruction is invalid, any changes made within the transaction are discarded.
+A program may be written in any programming language that can target the
+Berkley Packet Filter (BPF) safe execution environment. The Solana SDK offers
+the best support for C programs, which is compiled to BPF using the [LLVM
+compiler infrastructure](https://llvm.org). Alternatively, a client might
+choose to bypass LLVM and use Python, Lua or C++ to generate BPF directly via
+the [BPF Compiler Collection](https://github.com/iovisor/bcc) (BCC).
 
 ## Storing State between Transactions