The equivalence of manifolds under continuous deformation within the embedding space. Knots of opposite chirality have ambient isotopy, but not regular isotopy.
Regular Isotopy
See also
Ambient IsotopyExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Regular Isotopy." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RegularIsotopy.html