Different States

The Visual Basic Editor can be in any of a possible three states.
The title bar in the Visual Basic Editor indicates which mode you are currently in.
The caption in the title bar of the VBE indicates which mode you are currently in. When you are in design mode nothing is displayed.

Design Time

This is before or after you run your macro. All the time you are writing code or designing userforms you are in design mode.
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The main VBE window will append a "[design]" at the end of your project name when it is in design mode.
When you are writing your code you are in design mode although there is no [design] appended to your project name.
You can design userforms, draw controls, and use the Properties window to set or view property settings.
A lot of the debugging tools are unavailable while in this mode however you can set breakpoints and creating watch expressions.

There are a number of ways you can enter design time
1) Use the Reset button on the Debug toolbar or Standard toolbar
2) Selecting (Run > Reset) when in break mode.
3) Use the Design Mode button on the Debug toolbar.
4) Selecting (Run > Design Mode)

Run Time

This is when your macro is actually running. [running]
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The main VBE window will append a [running]" at the end of your project name when it is in run mode.
You can view code but you cannot make any changes
There are a number of ways you can enter run time
1) Use the Start (or Continue) button on the Debug toolbar or Standard toolbar
2) Selecting (Run > Run Sub/Userform)
3) Pressing (F5)

Break Mode

This is when execution of your macro has been temporarily suspended. This could be due to an error occurring, a breakpoint being reached or a deliberate interruption. [break]
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The main VBE window will append a "[break]" at the end of your project name when it is in break mode.
Break mode is entered when a running procedure stops because of either an error in the code or a deliberate interruption.
When in break mode - it is not advisable to make any significant changes, you are likely to get a Dr Watson.
It is possible to edit code when you are in break mode although this not recommended and will occasionally crash your application.
A breakpoint is a setting on a line of code that will cause the execution to be interrupted before that line of code is executed.
Code execution then enters what is known as "break mode".

There are a number of ways you can enter break-mode:
1) Use the Break button on the Debug toolbar or Standard toolbar
2) Selecting (Run > Break)
2) Press (Ctrl + Break) or (Esc)
3) Include a "Stop" statement in your code. This is the only way to save a breakpoint in your code.
5) Add a watch statement (Debug > Add Watch) with either of the Break options set "Break when True" or "Break when changed"