Definitions pentagram and pentacle
At the most basic level a pentagram is a five point star shape constructed with 5 straight lines
A pentacle is the same as above, but is normally situated inside of a circle.
Both can have many elaborations and extensions such as colour, peripheral icons, line variations etc.
Etymology - Pentagram
From the Greek - Pentagrammon
Penta = 5 and Gram = "that which is Marked or Written" So five markings, five lines.
Etymology - Pentacle
This one is a bit more contentious there are multiple schools of thought on how the word came about.
Some believe it has roots in older French words concerned with pendants and talismans. Other give is a more Latin derived backstory in that it comes from the Latin word pentaculum, with the prefix penta- which means five, and -culum, which translates to instrumentality.
The ring can sometimes be said to represent unity and balance.
No matter how these words came to be, the shapes and meanings have a much longer and detailed usage then what sits in modern memory.
How did the pentacle-pentagram become associated with Devil worship?
It was Eliphas Levi, a French poet, writer and sage who first tarnished the good image of the five pointed star. He claimed an inverted pentacle signifies the devil himself. According to Levi, when two points of the pentacle are pointed upwards, the image of Satan, with his horns, is conjured.
Peace of Mind
Rest assured that our use of the five pointed star has nought to do with satanic worship and all to do with nature and all things wholesome. For most of history the pentagram-pentacle was associated with positive images. It was even at one point the sign used for Christianity before the Cross was adopted.
I am sure that current users of the symbol are of strong enough minds to imbue the pentagram-pentacle with whatever meaning their beliefs may require.
More to come soon - Posted 9th day of June 2022