Tobacco is smoked in pipes, cigars and cigarettes.
The weed causes lung cancer which is often fatal, as well as heart disease and other diseases, some deadly. Nicotine makes it harder for a woman to conceive and most women want Children at some time in their lives, during pregnancy smoking harms the baby.  Men who use tobacco produce fewer sperm and lower quality sperm making it harder for them to give their partners a baby. Alcohol and Drug abuse also reduce male fertility.  Whichever sex you are if you want a baby now or may want children later don't smoke and keep off other bad stuff. 
Nicotine in tobacco is addictive so smokers spend a lot of money on tobacco products. Tobacco is of course very profitable for companies producing it.
Setting tobacco on fire
Smoking is the strange act of setting tobacco on fire and breathing it in, in order to intake nicotine. It has few or no health benefits and causes lung cancer as well as other cancers like throat cancer. Smoking can make users cough up a shitload of mucus every 30 seconds.
The evidence that tobacco is harmful is stronger than the evidence that cannabis is harmful.