Linking a YouTube channel to a Google+ page lets you:
- A) manage one channel from one Google account and let multiple people manage a channel
- B) manage one channel from one Google account
- C) manage multiple channels from one Google account
- D) manage multiple channels from one Google account and let multiple people manage a channel
If you connect your YouTube channel to your Google Account: Only you can access the YouTube channel and you have to use your Google Account. The YouTube channel uses the same name and photo as your Google Account (and rest of your Google services, like Gmail or Google Docs). But You can use Use a Brand Account. A YouTube channel connected to a Brand Account can be shared across multiple accounts.
Read more here: https://support.google.com/youtube/answer/4642409