The name was changed from SSL to TLS as part of the adoption in IETF. I imagine different people had different motivations, but in part it was a signal that it was going to be controlled by IETF rather than Netscape.
As far as compatibility goes, TLS is backward compatible with SSLv3 [0] in that the client can send a ClientHello that is acceptable to both SSLv3 and TLS servers and the server can select the version to use.
Re: the version number, we're now on TLS 1.3, so I guess that would be SSLv7.
[0] The situation is more complicated with SSLv2, which had a different ClientHello format.
Not quite.
The name was changed from SSL to TLS as part of the adoption in IETF. I imagine different people had different motivations, but in part it was a signal that it was going to be controlled by IETF rather than Netscape.
As far as compatibility goes, TLS is backward compatible with SSLv3 [0] in that the client can send a ClientHello that is acceptable to both SSLv3 and TLS servers and the server can select the version to use.
Re: the version number, we're now on TLS 1.3, so I guess that would be SSLv7.
[0] The situation is more complicated with SSLv2, which had a different ClientHello format.