Imagine you have a newsstand and you start to pay attention to how many magazines you sell each month for one year to understand which months you sell more and which months you sell less. So what you want is to understand the trends of your business.
So, after a year, you are able to draw a graph that represents all sales for this year per month as follows:
So, as we can see above, We have the sales of your newsstand from January to August. The x-axis indicates the months of the year and the y-axis indicate the number of magazines sold. We can see for January you sold 15 magazines and the number increased for February and Mars. Between Mars, April and May, it stayed constant and from May to August it decreased. It is represented by the line in red, where we have first an increasing trend, after a constant trend and finally a decreasing trend. So that is how it works, and now you can understand and explain how a graph of sales trends works and which kind of images you have to look for.