In the following output, what does the 1 in the b column indicate?

While a process might be waiting, `vmstat`'s `b` column specifically indicates blocked, not necessarily swapped, which is shown by `swpd` or `si`/`so` columns.

This is too general; the `b` column specifically denotes a *blocked* state, which is a particular type of waiting often for I/O resources.

A process waiting on a parent to check its exit value is a 'zombie' process, which is typically shown in `ps` output, not directly by `vmstat`'s `b` column.

In `vmstat` output, the 'b' column (blocked) under the 'procs' heading specifically represents the number of processes that are in an uninterruptible sleep state, which most commonly occurs when they are waiting for I/O operations (like disk or network I/O) to complete. A value of '1' means one process is in this blocked state.