It is easy to set up a transverse wave on a string.  See Experiment 1.

A node is a particle in a wave which does not move and can be seen on a wave set up on a string.  An antinode is the point of greatest movement in the wave.

In order for a note to be produced on a string, a whole number of waves must fit on it, so when a string is forced to vibrate, for example on a violin, the sound produced depends on the length of string vibrating.  Different notes can be produced by altering the length of the string.

When a string is plucked, it vibrates at its resonant (natural) frequency.