Trade-off bias variance is another very important concept in Statistics/Machine Learning.
The data points in blue comocome from $y(x)=\sin(x)+\epsilon$, where $\epsilon$ has a normal distribution. The red curves are estimated using different samples. The figure "Large Variance and Small Bias" presents the original model, which is Radial basis function network with 24 gaussian bases.
The figure "Small Variance and Large Bias" presents the same model regularized.
Note that in the figure "Small Variance and Large Bias" the red curves are very close to each other (small variance). The same does not happen in the figure "Large Variance and Small Bias" (large variance).