Hello, Inannon.
Voodoo is a religion (spiritual path). It originated in the area now known as Benin, in West Africa. A major variant or derivative form of it developed among French-Creole slaves in Haiti, in the Caribbean Ocean, where it acquired characteristics of Catholicism. After independence and end of slavery, it remained isolated for decades, but in recent years, a re-Africanization of Haitian Voodoo has led some (but not all) practitioners to limit or remove the Catholic aspects of practice. The word Voodoo is translated into English as Spirit. The religion of Voodoo, in its various forms, is like any other religion in that it has its own clergy, liturgy, and creed.
Hoodoo is a form of folk magic. Its practitioners are primarily African American Protestant Christians. Their spiritual path is Christianity. It developed primarily in the slave holding states of the southern United States and spread north rapidly during the early 20th century as African Americans settled in urban areas above the old Mason=Dixon line. The word hoodoo is Gaelic (Scottish and Irish) and means an eerie or spiky ghost or a haunting or haunted place (and was, in ancient times, related to Gaelic beliefs about the spiky Hawthorne tree). It entered African American speech as a loan-word via the contact that African American sailors and longshoremen had with Irish, Scottish, and American Scots-Irish sailors and longshoremen during the 19th century. Hoodoo, not being a religion, has no clergy, liturgy, or creed; rather, its practitioners generally hold to the liturgy and creed of Protestant Christianity, with a small number avowing adherence to Catholic Christiany or to Spiritualism, according to the beliefs of their families or their own personal inclinations. .
Do not confuse words that rhyme. Do not think that all people with dark skin are devotees of a pantheon of deities and lesser spirits from Benin.
Observe.
Ask.
Study.
Learn.
You can read a lot more about these subjects here:
Hoodoo History:
http://luckymojo.com/hoodoohistory.html
Hoodoo and Religion:
http://luckymojo.com/hoodooandreligion.html
P.S. The English-language word "witchcraft" used to have one meaning -- the English practice of folk-magic and folk-medicine. Since the 1950s, it has developed a second meaning, and -- spelled with a capital W, as Witchcraft -- it may now refer instead to a new or revivalist religion (or spiritual path) that includes elements of goddess-centered or nature-centered worship and veneration with its own clergy, liturgy, and creed.
Good luck -- and if you are interested in the folk-magic of African Americans, you have come to the right pace.