\underline{EM waves} are \underline{transverse} waves: $\vec{E}\perp\vec{v}$, $\vec{B}\perp\vec{v}$

\underline{Velocity} $v$, \underline{period} $T$, \underline{wavelength} $\lambda$ of the wave
$$
  v = {\lambda\over T} = \lambda f
$$

\underline{Traveling waves}:
$$
  y=A \> \sin \phi = A \> \sin \left( \frac{\displaystyle 2\pi}{\displaystyle T} t - \frac{\displaystyle 2\pi}{\displaystyle \lambda} x + \phi_0 \right) = A \> \sin ( \omega t - kx + \phi_0 )
$$
where \underline{angular frequency} $\omega=2\pi/T$, 
\underline{propagation constant} $k=2\pi /\lambda$

