The solar wind is a collection of streams of particles that originate on the Sun, and are ejected through coronal holes. Because the particles move radially as the Sun rotates, the wind traces out a pinwheel pattern throughout the solar system. The arm representing individual streams from specific coronal holes. The density of particles in the wind is about 1-1 nuclei per cubic centimeter near the Earth's orbit, traveling at 200 - 900 km/sec. It consists mostly of protons and alpha particles ( hydrogen and helium nuclei) and electrons.
At these densities, they have no dynamical effect on a spacecraft, unless it is equipped with a so-called solar sail. Such sails are under serious study by NASA because an acre or more of light-weight sail could intercept enough of the particles to provide modest but sustained acceleration. Comets are affected by the solar wind both via a magnetic interaction ( magnetic field of solar wind interacts with cometary 'ion' tail); and by direct collisions with cometary material. The cross section for an electromagnetic interaction is larger than for direct atom-nuclei collisions so that's why cometary tail physics is more dependent on the interaction with the solar wind magnetic field. Comets also have 'dust' tails, but these are simply particles moving along the orbit of the comet which are not affected by the wind as is the ionized gas component.