It was tension. After the British won the French and Indian war, they were lead to severe war debts and since the British ruled the colonies, they decide to enforce taxes and even more laws.
Then it lead to soldiers sailing over to the colonies to secure the tax money.
Now the british is on the colonies’ property, they’re taking part time jobs in the Americas and the colonists felt like they were taking all the jobs from them.
Eventually colonists starts harassing the British and then I think there was a false alarm which made the British troops shoot the colonists and bam, thats the boston massacre.