Hard, soft and other targets

[Montana Grizz]

There is a current thread that has attempted to answer whether aircraft are "soft targets" or perhaps "other".

It does not specifically address my question.

What is a "Hard" target, what is a "Soft" target and what the hell are "Other" :conf:

It has been suggested that any unit with a "Red" defensive factor is a hard target, thereby lumping the Russian BA-64 AC in the same category as the KV-1?

If this is true, then what is the difference between "Soft" and "Other"?

The German AA HT's (SdKfz 6/2 and 10/4) are unarmored vehicles. Are they "Soft" or "Other"?

I've been thinking for years that infantry are "Other", but perhaps I have been setting my Op fire improperly.

I would really appreciate a definitive answer.

Thank you,

Pat