The Iris dataset consists of 50 examples from each of the three species of Iris (Iris-setosa, Iris-versicolor and Iris-virginica). Four features were measured from each sample: The length and width of petals and sepals, in centimeters. Based on the combination of this four features, Fisher developed a linear model to distinguish the species from each other.
The dataset contains a set of 150 records under 5 attributes - petal length, petal width, sepal length, sepal width and the types of flower. The Iris dataset is widely used as an introduction/hello world of machine learning