MNIST stands for the Modified National Institute of Standards and Technology database. It is a large dataset commonly used for training various image processing systems. The dataset consists of 70,000 handwritten digits, ranging from 0 to 9, and is widely utilized in the field of machine learning and computer vision. The MNIST dataset is divided into 60,000 training images and 10,000 testing images. Each image is a grayscale 28x28 pixel representation of a single digit. Researchers and developers use MNIST to benchmark algorithms and models, making it a fundamental resource for those working with image recognition tasks.