To compare fractions using models, it helps to

divide the models into the same number of equal pieces.

The first model is divided into two equal parts, and one part is shaded.

So, the first model shows $\frac{1}{2}$.

The second model is divided into three equal parts, and two parts are shaded.

So, the second model shows $\frac{2}{3}$.

To compare the fractions, it helps to divide the models into the same number of equal pieces. This is called finding a common denominator.

The least common denominator is the least common multiple of 2 and 3, which is 6. Divide both models into six equal parts.

The model with more parts shaded represents the greater fraction.

So, $\frac{1}{2}<\frac{2}{3}$.