See also the following links:

▎ENGLISH

Principal Component Analysis - Wikipedia
▸ https://en.wikipedia.org/wiki/Principal_component_analysis

Feature Extraction using PCA
▸ https://vitalflux.com/feature-extraction-pca-python-example/

▎日 本 語

主成分分析（PCA）って一体何をしているの？（理論編）
▸ https://qiita.com/oki_kosuke/items/70c7e0bcd7b534589f69

Weight by PCA - Rapidminer (JP)
▸ https://support.rapidminer.jp/rapidminer-studio/operators-list/9.5/modeling/feature_weights/weight_by_pca