on-on switch?

[zee]

While ordering switches, i came across a Lucas type "on-on" switch to use with "low-beam / high-beam".

EDIT: I might not have explained my question well. I am a complete novice at this.

When using a typical off/on switch with a relay, I can use NC and NO (87a and 87 I think) to power two accessories, so it acts like an on-on switch. If that's the case, then why does a dedicated "on-on" switch exist? Is it so we don't have to use a relay?