Difference between rise and raise.

What is the difference between the verbs rise and raise?"

Rise is an irregular verb: rise / rose / risen
Raise is a regular verb: raise / raised / raised

Although both of these verbs have the general meaning of "to move upwards", the main difference is that rise is an intransitive verb (it does not take an object), while raise is a transitive verb (it requires an object):

The sun rises in the east.
The temperature rose to 100 degrees.
Mary raised her hand.
The government is going to raise taxes.
As you can see from these examples, something rises by itself (nobody is pushing up the sun!), whereas something else is needed to raise something (Mary moved her hand upwards/The government make laws to increase taxes).

Allergies such as asthma and hay fever are continuing to rise around the world despite efforts to curb pollution, the principal suspect.
After rain, the river level rose and fell mightily, and the channels were mined with sunken tree limbs.
However, it is true that the footballer's weight has risen and fallen over the past few years.
... envelops the target in a substance, like a science fiction product, that is completely disabling. There is no need to kill; a gunman cannot even raise his arm to fire.
... she smiled broadly and raised a clenched fist at a crowd of airport workers.
For further examples, go to the Web Concordancer’s home page, type rise, rose, risen, raise, or raised into the 'search string' field, select any corpus in the 'select corpus' field, and then click on the 'search for concordances' button. You will get many examples of how the words are used.