The difference between “Igbo” and “Ibo”

I was reading up an article on titled: Nigerian child in diaspora and at the bottom of the article was a link to this youtube video.

I submit, the kids are really cute looking, with light brownish/whitish hairs etc….being taught how to say “Igbo Kwenu” all the way from Finland. Perhaps, these kiddies grow up to be Nigerian politicians, who knows….

It was after reading the article and viewing the video that the question popped in my mind: whats the difference between igbo and ibo?

A friend I caught up with online told me both are the same, while another said ‘igbos’ are the original people and ‘ibos’ are the decendants from the igbos. The third said ‘igbo’ is the people, ‘ibo’ is the language.

I did some research on google, but the infos I got was all about igbo history etc., anyway, to all the ‘Igbo’ and ‘Ibo’ people out there, please help me sort this out:
What is the difference between Igbo and Ibo.