# Time Series

## What is Time Series :

Time series is a series of data points collected at regular intervals over a period of time. It is a widely used statistical method for analyzing and forecasting trends and patterns in data. Time series data can be found in various fields such as finance, economics, meteorology, and engineering, to name a few.
Example 1: Stock Prices
One example of time series data is stock prices. Stock prices are constantly changing and can be collected over a period of time, such as daily, weekly, or monthly. By analyzing the stock prices over time, investors and analysts can forecast the future performance of a stock and make informed decisions about whether to buy or sell.
To analyze stock prices, various statistical methods can be used such as autoregressive integrated moving average (ARIMA) models and exponential smoothing. These methods take into account past values of the stock price and try to forecast the future values based on the trends and patterns observed in the data. For example, if the stock price has been consistently increasing over the past few months, the model may predict that it will continue to increase in the future.
Example 2: Temperature
Another example of time series data is temperature. Temperature data can be collected at regular intervals, such as hourly or daily, over a period of time, such as a month or a year. By analyzing the temperature data over time, meteorologists can forecast the weather and predict temperature trends and patterns.
To analyze temperature data, various statistical methods can be used such as linear regression and seasonal decomposition. Linear regression is a statistical method that helps to identify the relationship between two variables, in this case, temperature and time. Seasonal decomposition is a statistical method that helps to identify the trend, seasonality, and residual components of a time series data. For example, if the temperature data shows a consistent increase in temperature during the summer months and a consistent decrease in temperature during the winter months, the model may predict that the same trend will continue in the future.
In conclusion, time series data is a series of data points collected at regular intervals over a period of time and can be found in various fields such as finance, economics, meteorology, and engineering. By analyzing the data over time, various statistical methods can be used to forecast future trends and patterns and make informed decisions.