LaTeX vector symbols: The vec command makes a narrow arrow

\[
\vec{ v } \\~\\
\vec{ vector } \\~\\
\overrightarrow{AB} \\~\\
\Overrightarrow{AB}
\]

\[ \vec{ v } \\~\\ \vec{ vector } \\~\\ \overrightarrow{AB} \\~\\ \Overrightarrow{AB} \]

The vec command is easy to write but its arrow is relatively short. The second example shows the arrow of vec doesn't automatically adjust to the width of its base vector symbol. The arrow of overrightarrow is used for connecting points.