I’m not a big expert, but basically, tulpas are alters/sentient thoughtforms— personalities of their own and everything— who are purposefully created by their hosts. There’s a fairly welcoming community here who can tell you a lot more than I can, and I’m sure some of those who follow me can reblog and give more specific info. :)
Yes, torturebeginsathome answered the question very well. The term tulpa originated back from the monks of Tibet, who used the practice of creating a ‘tulpa’ as a mental exercise, and to learn about the nature of consciousness. There are many people in the tulpa community who believe tulpas can often explain instances of what might have been confused for paranormal or spiritual things—Some question if spirit guides, daemons, and other instances of people having other such invisible companions could have been tulpas created accidentally.
Most tulpas in the community do not front quite as often as it seems multiples tend to, I don’t know if this is because of the method of creation or perhaps the creator not having much dissociation in the beginning, either way, tulpas generally would be communicated with through headspace(often called wonderlands), or externally through imposition.
Imposition is essentially the practice that separates the tulpa community from most of the other plural communities I think, and it is where the roots in Tibet come in. The act of imposition is essentially creating a controlled hallucination, to trick the mind into seeing, feeling, hearing, perceiving the tulpa as physically as anyone else. This is a process that is wanted by many, though still a relative few have succeeded. Not every person who creates a tulpa wants to go through imposition, actually, but many do.
There are a few different websites about tulpas. Tulpa.info is probably the largest part of the community and where most of the information is located.
Uhhh anyway there’s a lot to it, I’m not sure if I’m the best at explaining it. Feel free to ask any questions.
Also, feel free to ask either of my tulpas. fuzzy-bastard and miss-giselle are their urls. Jaden’s usually the one who does the talking when it comes to the tulpa community lately anyway, haha.