A charged particles only interacts with a magnetic field if it is moving with respect to the field. A moving charge experiences a force in a direction perpendicular to the field lines its velocity if it is not moving parallel to the field. If it is moving parallel to the field, the experienced force is 0.
Electric fields, on the other hand, interact with charged particles even if they are motionless. The force experienced by the particles will be in a direction parallel to the field lines.