See also the following links:

▎ENGLISH

Time Series (Wikipedia)
▸ https://en.wikipedia.org/wiki/Time_series

Time Series Forecasting: Definition, Applications, and Examples
▸ https://www.tableau.com/learn/articles/time-series-forecasting

▎日 本 語

時系列の意味をわかりやすく
▸ https://imikaisetu.goldencelebration168.com/archives/2217

時系列分析の基本的なモデルをわかりやすく解説
▸ https://ai-trend.jp/basic-study/time-series-analysis/time-series-analysis/