No, swinging is swapping partners, not sharing. Sharing/NTR/cuckold/etc fall under the netorare tag.
It certainly is confusing, NTR, NTS, Sharing, Hotwifing, cucking, cuckhold, cuckqueening, Swinging, Spouse swapping, etc.
The way it is IRL, swinging is an open sexual relationship in a public environment. Spouse swapping is a subset of that in which only two or three couples are involved, usually in the same room but not always. Sometimes at the same time/location but not always.
Hotwifing is also a subset of that in which a man is proud of his female partner and wants her to express her sexuality. Usually it is done mutually, often the man is engaging with sex at the same time, but not always. It almost always involves voyeurism/exhibitionism.
Cuckholding is a separate thing and can be part of the swinging lifestyle. It is when the male is forced to watch the female partner have sex with others. Often its done with permission and encouragement of the male partner but not always. Sometimes is involves some humiliation or condescending dialogue.
Cuckqueening is just the female version of cuckholding. Cucking is the term for both.
Polyamory is a permanent or semi-permanent multiple partners always involving an emotional attachment. Polygamy involves multiple females, and Polyandry involves multiple males.
Sharing is the entire experience involving all of these things.
NTR / NTS is something I have only seen on this forum and is apparently some big deal for some reason. Neotare seems to be equivalent to cuckholding and Neoterase is equivalent to swinging, hot wifing or swapping.
My guess is that some insecure invididuals have problems with the inherent compersion in both of those since that triggers the fear of their inadequecy. (Which is almost always inaccurate and exaggerated.)
Compersion is the feeling of happiness or contenment or excitement of someone elses pleasure or achievement. It can be sexual of course which is why all of the above even exists. It can also be nonsexual in that a father is proud of his son in an athletic contest or a mother of her daughter getting married, etc.
)