\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english,greek]{babel}
\usepackage{tikz}
\begin{document}
Βλέπε εικόνα~\ref{fig:1}.
\begin{figure}\label{fig:1}
\centering
\begin{tikzpicture}
%\resizebox{\textwidth}{!}
\draw[step=0.5cm,gray,very thin] (-2,-1) grid (2,4);
\draw[->] (-2.2,0) -- (2.2,0) node[right] {$x$};
\draw[->] (0,-1) -- (0,4.2) node[left] {$y$};
\foreach \x in {-2,-1,1,2}
	\draw (\x,0) -- (\x,-0.1) node[below] {\x};
\foreach \y in {1,2,3,4}
	\draw (0,\y) -- (-0.1,\y) node[left] {\y};
\draw[scale=1,domain=-2:2,smooth,variable=\x,blue,thick]plot({\x},{pow(\x,2)})node[right]{$y=x^2$};
\end{tikzpicture}
%}
\caption{Συνάρτηση $y=x^{2}$}\label{fig1}
\end{figure}
\end{document}
