Step 1 reads the data.
Step 2 uses the ts function to generate a time series object based on the raw data.
Step 3 uses the plot function to generate a line plot of the time series. We see that the time axis does not provide much information. Time series objects can represent time in more friendly terms.
Step 4 shows how to create time series objects with a better notion of time. It shows how we can treat a data series as an annual, monthly, or quarterly time series. The start and frequency parameters help us control these data series.
Although the time series we provide is just a list of sequential values, in reality, our data can have an implicit notion of time attached to it. For example, the data can be annual numbers, ...