Why are they called sects in Islam and not denominations?

I understand that Islam has different ideologies and ways of interpreting the Qur'an, and those people with like views will stay together and call themselves a group. Though I wonder, why is each group called a sect when that word has a normally negative connotation to it? Is there a historical reason for using the word sect? Why, instead, isn't each group called a denomination? Is that a strictly Christian word or can it be used?