Bind
Combining two vectors into a third that resembles neither, and can be taken apart again.
Like you're twelve
Put a letter in an envelope and seal it. The sealed envelope does not look like the letter, and it does not look like the envelope you started with — it is its own thing. But hand it to someone holding the right opener and the letter comes back out.
That is binding. It is how you say colour is red in one vector: bind COLOUR to RED and you get a thing that means the pairing, not either half.
Precisely
Bind is circular convolution, computed through the FFT. The result is near-orthogonal to both operands, which is what distinguishes it from bundling — a bundle resembles its parts, a binding hides them.
Binding is what gives a role/filler slot without a schema. bind(GENRE, scifi)
is a vector meaning "genre is scifi", and it collides with nothing else in the
space. Bind several such pairs, bundle them together, and one vector holds a
whole record.
The inverse is Unbind, and it is approximate — which is why every serious use of binding also needs a Cleanup memory.