When we go to Makkah to perform Hajj or Umrah we put on our Ihram.
Before putting on Ihram a pilgrim must do Ghusl and make his niyyah.
In ihram the pilgrim wears two pieces of cloth and sandals or shoes that do not cover the top of his foot. He can not use perfume or cover his head. He can not cut hair or his nails while he is in Ihram. (A pilgrim can cut his hair and nails and wear perfume before putting on his Ihram). He must not fight or argue or hunt. He can not get married until he is out of ihram. Men must cut or shave their hair to remove their Ihram
Women in ihram can wear anything that covers them properly and they do not cover their faces. Women do not have shave their hair they only cut a little hair.
At Hajj a pilgrim must make his sacrifice before removing his Ihram.