The Levene's or Modified Levene test is used to evaluate the homogeneity (equality) of Variances assumption required for Anova and other statistical procedures. It has an advantage over the Bartlett test, another test for homogeneity of multiple Variances, in that it dosn't require that the sample data be normally distributed.
The original test used just the Means in the analysis, but the Modified Levene Test allows use of the median or trimmed mean.
Homogeneity of Variances
Levene Test: - http://www.itl.nist.gov/div898/handbook/eda/section3/eda35a.htm