The outward flux of solar particles and magnetic fields from the sun. Typically, solar wind velocities are near 350 km/s  and proton and electron densities are near 5 per cubic centimeter. The total intensity of the interplanetary magnetic field is nominally 5 nT .
ON-LINE GLOSSARY OF SOLAR-TERRESTRIAL TERMS of National Geophysics Data Center

A continuous plasma stream expanding into interplanetary space from the sun's corona. The solar wind is present continuously in interplanetary space. After escaping from the gravitational field of the sun, this gas flows outward at a typical speed of 400 km per second to distances known to be beyond the orbit of Pluto. Besides affecting Earth's weather, solar activity gives rise to a dramatic visual phenomena in our atmosphere. The streams of charged particles from the Sun interact the Earth's magnetic field like a generator to create current systems with electric potentials of as much as 100,000 volts. Charged electrons are energized by this process, sent along the magnetic field lines towards Earth's upper atmosphere, excite the gases present in the upper atmosphere and cause them to emit light which we call the auroras. The auroras are the northern (aurora borealis) and southern (aurora Australis) lights.
NASA Earth Observatory

Solar Wind - The outflow of charged particles from the solar corona into space. Because of the high temperature of the particles of the corona (mostly protons and electrons), they are moving at speeds higher than the solar escape velocity. At the orbit of the Earth, these particles are moving at about 500 km/sec. Some of these particles are captured by the magnetic fields of the planets, forming their magnetospheres.
Atmospheric Chemistry Glossary