\newcommand{\point}[2]{
\node [label=above:$#1$] (#1) at #2 {};
}
\begin{tikzpicture}[]
\begin{scope}[every node/.style={fill=black, shape=circle, inner sep=1pt}]
\point{a}{(0,0)}
\point{b}{(1,0)}
\point{c}{(2,0)}
\end{scope}
\draw (a) -- (b) -- (c);
\end{tikzpicture}