Data normalization is important for several reasons. First, it can reduce the impact of data variability and noise on the analysis and modeling process. For instance, if you want to use a linear regression model to predict an outcome based on multiple features, you need to make sure that the features are on the same scale and have similar variance, otherwise some features might dominate or bias the model. Second, it can improve the performance and convergence of algorithms that use numerical computations, such as gradient descent, neural networks, and clustering. For example, if you want to use a neural network to classify images, you need to normalize the pixel values to a range of 0 to 1, so that the network can learn faster and more effectively. Third, it can enhance the interpretability and usability of data and results. For example, if you want to visualize the data or present the results to a non-technical audience, you need to normalize the data to a meaningful and intuitive scale, such as percentages, scores, or ratings.