A Solar Eclipse is a New Moon that is so precisely aligned that the Moon casts a shadow on the Earth. This precision makes the New Moon extra powerful. There are at least 2 solar eclipses per year. This precision happens when the New Moon is conjunct one of the Lunar Nodes, within about 18°.
Astrologically, solar eclipses bring very powerful energy, similar to a New Moon but more intense. They often initiate new processes of growth in your life, which is often challenging, difficult or disruptive.
The Full Moon just before or after a solar eclipse is always a Lunar Eclipse. Eclipses typically happen twice a year, about 5-5½ months apart. However, sometimes there are 3 eclipses in a row – lunar-solar-lunar or solar-lunar-solar. In that case, the two of the same type are usually partial eclipses.
When a solar eclipse is visible from your location, it happens during the day. The disc of the Moon passes over the disc of the Sun, blocking the Sun's light. During a total solar eclipse, the Moon will completely cover the Sun. In a partial solar eclipse, the Moon will cover only part of the Sun, looking like a bite has been taken out of it. In an annular solar eclipse, the Moon is farther away from the Earth than usual, so it looks smaller than the Sun and there is a "Ring of Fire" around the Sun.
WARNING: You must never watch a solar eclipse without proper eye protection or you can damage your eyes, often permanently. Find out more about the astronomy of eclipses. On the other hand, it's completely okay to look directly at a lunar eclipse. How can you tell if it's a solar or lunar eclipse? Easy! Assuming it's visible from your geographical location: if it's nighttime, it's a lunar eclipse. If it's daytime, it's almost certainly a solar eclipse.
It's okay to watch a lunar eclipse without any eye protection (it's the solar eclipse that can cause eye damage). When it's a total lunar eclipse, you'll see the Moon turn dark orange or red. A partial lunar eclipse may just turn a bit darker on one side of the Moon. The eclipse typically lasts for several hours and you need to be in the right place on Earth to be able to see it.
Eclipse season is usually an intense time of the year when many changes take place. The house in your natal chart where the eclipse happens may under go changes or issues may arise that need to be dealt with. Eclipses have a reputation for being harbingers of bad news, but more often they will mostly just bring some intensified or dramatic energy for a short time. On the other hand, they can sometimes set changes in motion that play out for weeks, months or even years, depending on how big the changes are.