Principal component analysis (PCA) reduces a numeric dataset to a few summary features called components. Each component is a weighted combination of the original features, making complex tabular data easier to visualize. section 2.4.3
Use PCA as an exploratory step: plot the reduced dimensions to look for patterns, isolated clusters, or possible anomalies before modeling. Because PCA is linear, it may miss nonlinear structure; compare it with SVD, t-SNE, or UMAP when appropriate. section 2.4.3









