You can’t move out of bed with the flu. No energy. High fever. Aches all over, which are relieved somewhat with drugs like ibuprofen that also lowers the fever. No congestion. A cough (usually not very severe, but it can be).
With a cold, you might start with a sore throat for 2 days, might not, then you get congested, blow your nose enough times to finish two boxes of tissues in a 4 days, and it usually is over with in 7 days start to finish. No fever in adults. Able to function, work, etc, but miserable doing it.
If you don’t know the difference between a cold and flu you haven’t had the flu, or had it so long ago you don’t remember. The flu knocks you on your ass.