A line graph reflects continuous data as points plotted on a graph which are connected by a line.It is a way of showing how two variables or pieces of information are related, their inter-dependence and how they can vary depending on each other.
Line graphs are a popular way of presenting statistics. They are particularly helpful in studying and comparing trends over a period of time. They also help in inferring interim data as well as predicting future trends. So, they can be used for direct comparisons to show growth.
Line graphs can also be used while graphing multiple data sets. Comparing and studying multiple data sets becomes much easier while using line graphs. However, it is important to give a key to enable better understanding of the graph.
It is important to use the correct scale while drawing line graphs so as to display the correct information or give the correct impression. Using the wrong scale may defeat the whole purpose.
Line graphs are generally used to show stock market trends, temperature comparisons etc for a particular week, or any particular time-period.
3D line graphs are another form of line graphs. They are also used to compare trends over a particular period of time, but in a 3D format.
Line graphs are also called the frequency polygon, the edge graph, the adjoint graph, the interchange graph or the derived graph.
One of the limitations of line graphs is that they can be used only with continuous data.