There are many different types of external radiotherapy. The type you have depends on your type of cancer and it's position in the body.
Conformal radiotherapy is also called 3D conformal radiotherapy or 3DCRT. It is a very commonly used type of radiotherapy.
Intensity modulated radiotherapy (IMRT) is a treatment for cancer. It is given in a hospital or specialist centre.
Image guided radiotherapy (IGRT) uses different scans and X-rays to treat an area of cancer.
Stereotactic body radiotherapy (SBRT or stereotactic ablative radiotherapy (SABR)) is a way of giving radiotherapy to a tumour from different directions.