anova() is used to compare the nested models.
Analysis of variance, or ANOVA, is a statistical method that separates observed variance data into different components to use for additional tests. A one-way ANOVA is used for three or more groups of data, to gain information about the relationship between the dependent and independent variables.
Analysis of variance (ANOVA) is a statistical technique that is used to check if the means of two or more groups are significantly different from each other. ANOVA checks the impact of one or more factors by comparing the means of different samples. Another measure to compare the samples is called a t-test.A factorial ANOVA is an Analysis of Variance test with more than one independent variable, or “factor“. It can also refer to more than one Level of Independent Variable.
For example, an experiment with a treatment group and a control group has one factor (the treatment) but two levels (the treatment and the control).