Wikipedia: "Economic Indicators"
Read this article.
In this article, you will observe the set of variables for the leading indicator, and you should be able to draw comparisons between it and the coincident and the lagging indicators.
Unlike the leading economic indicator, the coincident indicator provides an estimate of the current state of the economy. In this reading, you will observe the set of variables for this indicator, and you should be able to draw comparisons between this and the leading and the lagging indicators.
Unlike the other two indicators, the lagging indicator provides an estimate of the state of the economy after the fact. For instance, the unemployment rate, as a lagging indicator, will decrease (increase) after an economic expansion (contraction) already began. In this reading, you will observe the set of variables for this indicator, and you should be able to draw comparisons among this and the leading and coincident indicators.