bash - What is the difference of 'exec cmd &' and 'cmd &' in bash scripting?

Question

What is the difference between the following fork statements ?

1. command &
2. exec command &

You can use wait $! for both statements. In my test I have found no difference in the behavior - but maybe I'm missing something.

Answer 1

既存のプロセスを新しいプロセスに置き換えたり、新しいプロセスをバックグラウンドで実行したりすることはできないため、オーバーライド&します。exec