Not a silly question at all.

Both are dreadful states to be in, but I know that there is a difference from being Depressed and suffering from Clinical Depression. As a general rule being depressed 'most times than not' manifests from outside influences & negative life events. However Clinical Depression can manifest as a secondary issue from chronic illness, and/or faulty/imbalanced brain chemicals. Hence sometimes we witness those who on the outside seem to have the 'perfect life' fall victim to clinical depression...even though outwardly there are no apparent influences to cause said 'depression'.

This is not to say that someone who is going through depression won't develop clinical depression, as feeling low & despondent can wreak havoc on an otherwise healthy person.

My explanation of how the 2 differ may not be as exacting as I would like.....But I hope that makes things a little clearer.