Ah the usual "I've had flu" crowd 
Can't say I've ever experienced it myself, luckily. I have had very bad colds which have lasted the best part of a working week.
The biggest distinction I can make from a bad cold/flu is that you will still recover from a cold, yet the Flu has the potential to kill you. Instead of 4 days off sick you are likely to be out of action for 2-3 weeks.
This is why I found the whole "Swine Flu" debacle quite lol worthy. Due to it killing basically no one in the developed world and lasting a few days with no real chance of killing you if caught and such.
I'm not flaming those who've said they have had it, or those with it now (or those with very bad colds).
The main reason I say all this is that someone at my place of work still uses it at least twice a year with the old chestnut "Oh, I was off yesterday and the day before....touch of the flu".

Can't say I've ever experienced it myself, luckily. I have had very bad colds which have lasted the best part of a working week.
The biggest distinction I can make from a bad cold/flu is that you will still recover from a cold, yet the Flu has the potential to kill you. Instead of 4 days off sick you are likely to be out of action for 2-3 weeks.
This is why I found the whole "Swine Flu" debacle quite lol worthy. Due to it killing basically no one in the developed world and lasting a few days with no real chance of killing you if caught and such.
I'm not flaming those who've said they have had it, or those with it now (or those with very bad colds).
The main reason I say all this is that someone at my place of work still uses it at least twice a year with the old chestnut "Oh, I was off yesterday and the day before....touch of the flu".