Rise is a verb .It means to get up with one's own effort without the help of somebody else.It also means increase.This verb does not have an object or a complement.
The three forms of 'rise' are: rise- Present tense, rose-Past tense and risen -Perfect tense.
Examples: The sun rises in the morning.(Present tense)
The chairman rose from the seat to address the gathering.(Past tense)
The sky is bright because the sun has risen.(Present perfect tense)
Raise is also a verb. It means to lift or elevate an object. It also means to increase something.The verb must have a complement.
Example: Sometimes the government raises the prices of essential commodities.
My friend worked hard and raised his grade.(Past tense)
The government has raised the price of petrol .
The population of India rises alarmingly every year.
The clever crow threw some pebbles into the water and the water level rose.
John has risen early because he has a test.
Students usually raise their hands to answer a question.
The minister raised an important question in the parliament.
The greedy money lender has raised his interest rates.