Our aim in this study is to provide information about mammography devices commonly used in screening and diagnosis of breast diseases and the type of energy used in these devices. Mammography, which is widely used for the early diagnosis of breast cancer, is recommended every 2 years for the early diagnosis of breast cancer in women between the ages of 40-69 in our country. Breast cancer is the most common type of cancer in women and ranks second in cancer related deaths in the world. Low energy (25-40 KVp) x-rays are used in mammography devices. There are two different mechanisms that produce X-rays: Bremsstrahlung (braking) X-rays and characteristic X-rays. One of them is Bremsstrahlung (braking) X-rays and the other is characteristic X-rays. 15% characteristic and 85% x-rays are used in imaging. Only Bremmstrahlung (braking) x-rays are used in treatment. Mammography is a technique of imaging the breast using x-rays. Mammography is a method of taking a imaging of the breast. The breast is compressed between two layers and a radiographic image is obtained. Mammography can be 2-dimensional or 3-dimensional (tomosynthesis) depending on the available equipment or the purpose of the examination. Mammograms are applied in two ways for screening and diagnosis. Screening mammography is performed for the early diagnosis of breast cancer in women with no complaints. The European Imaging Association primarily recommends screening with digital mammography rather than conventional mammography or phosphor-plate computed radiography. In the Digital Mammography System, the X-ray tube moves over the breast area and takes high-resolution, high-contrast images from various angles. The images are reconstructed in 3D to provide accurate information about the location and status of the lesion.