Components in Time Series

The various forces at work, affecting the value of a phenomenon in time series, can be broadly classified into the following four categories, commonly known as the ‘ components of a time series’ some or all of which are present in a given time series in varying degrees.
secular Trend or long term movements..
periodic changes of short-term fluctuations..
random or regular movements.
Moving average method of finding the trend:
The moving average method involved measurement of trend by smoothing out the fluctuations of the data by means of a moving average.