3.2.3 explanation

3-Add-simulated-motors.md

@@ -146,6 +146,16 @@ index 588dda7..8fddfc1 100644
 ```
 </details>
 
+
+<details>
+<summary>what does this mean?</summary>
+
+The `st.cmd.Linux` file is the IOC startup script which is responsible for initializing the EPICS environment, loading database definitions, and starting the IOC.
+The command `source iocsh/motors.iocsh` is used to execute the `motors.iocsh` script in the current shell environment. 
+After you make this modification and run the startup script, it will execute the commands in `motors.iocsh` as part of the IOC startup process, setting up the motor instance as specified in the `motors.iocsh` file.
+
+</details>
+
 ### 3.3 Run the IOC
 
 Start the IOC in a screen session: