A physical package can be hot swapped if it is possible to replace the element with a physically different but equivalent ...

A physical package can be hot swapped if it is possible to replace the element with a physically different but equivalent one while the containing package has power applied to it (i.e., is 'on').  For example, a disk drive package inserted using SCA connectors is removable and can be hot swapped. All packages that can be hot swapped are inherently removable and replaceable.