State the four main components of a time series.

1. Trend: The long-term movement or direction of the data, which can be increasing, decreasing, or stable over time.

2. Seasonality: Patterns that repeat at regular intervals, such as daily, weekly, monthly, or yearly fluctuations.

3. Cyclical variations: Longer-term patterns that are not necessarily regular or predictable, such as economic cycles or business cycles.

4. Random fluctuations: Unpredictable or irregular variations in the data that are not explained by trend, seasonality, or cyclical patterns.

1. Trend
2. Seasonality
3. Cyclical
4. Irregular