The Sugar Act was passed in 1764 and made it so the colonists had to pay a tax when buying sugar.
Great Britain passed the Sugar Act onto the colonists because they needed money to pay for the debts of the French and Indian War. They also were providing the colonist's protection with soldiers, so they felt like they could tax them and they didn't have the right to complain about it.
The colonists were not happy with this tax. There were numerous other taxes besides the Sugar Act and every single one made the colonists unhappy. They believed that being taxed was unfair, as they had nobody in the British Parliament to vouch for them. This is known as "taxation without representation," and was a big reason why the colonists wanted their independence from Great Britain.