Step 1: Formula for \( GL_2({F}_3) \).
The general linear group \( GL_2({F}_3) \) consists of all invertible \( 2 \times 2 \) matrices over \( {F}_3 \). Its size is:
\[
(3^2 - 1)(3^2 - 3) = 8 \times 6 = 48.
\]
Step 2: Conclusion.
The number of elements in \( GL_2({F}_3) \) is \( {48} \).