\documentclass{standalone}
\usepackage[active,tightpage]{preview}
\usepackage{tikz}
\usetikzlibrary{trees,shapes.geometric,positioning,arrows.meta,fit}

\usepackage{anyfontsize}
\renewcommand{\normalsize}{\fontsize{14pt}{16pt}\selectfont}

\PreviewEnvironment{tikzpicture}

\pgfdeclarelayer{bg}
\pgfsetlayers{bg,main}

\begin{document}

\begin{tikzpicture}[
    line width=1pt,
    minimum size=1.5cm,
    inner sep=-1em,
    scale=2,
  ]

  \begin{scope}[
    local bounding box=plot-left,
    level distance=1.2cm,
    every node/.style={circle,draw},
    level 1/.style={sibling distance=1cm},
    level 2/.style={sibling distance=1cm},
    level 3/.style={sibling distance=1cm},
  ] 
  
  \node (A-1) {}
    child { node {$x$}
      child { node {$z$} }
      child { node {$w$}
        child { node {$u$} }
        child { node (B-1) {$v$} }
      }
    }
    child { node {$y$} };
  
  \end{scope};

  \begin{scope}[
    xshift=3cm,
    level distance=1.2cm,
    every node/.style={circle,draw},
    level 1/.style={sibling distance=2cm},
    level 2/.style={sibling distance=1cm},
  ] 
  
  \node (A-2) {}
    child { node {$z+u$} 
      child { node {$z$} }
      child { node {$u$} }
    }
    child { node {$v+y$}
      child { node {$v$} }
      child { node {$y$} }
    };
  
  \end{scope};

  \begin{scope}[
    xshift=6cm,
    level distance=1.2cm,
    every node/.style={circle,draw},
    level 1/.style={sibling distance=1cm},
    level 2/.style={sibling distance=1cm},
    level 3/.style={sibling distance=1cm},
  ] 
  
  \node {}
    child { node {$z$} }
    child { node {$w+y$}
      child { node {$w$}
        child { node (B-2) {$u$} }
        child { node {$v$} }
      }
      child { node {$y$} }
    };
  
  \end{scope};

  \draw [->] ([xshift=1em]A-1.0) 
    -- node[below,pos=0.5] {\begin{tabular}{c}Double\\Rotation\end{tabular}} 
    ([xshift=-1em]A-2.180);
  \draw [->] ([xshift=1em]B-1.0) 
    -- node[above,pos=0.5,yshift=-10pt] {Single Rotation} 
    ([xshift=-1em]B-2.180);

\end{tikzpicture}

\end{document}
