What does "welcome" mean?

あらすじ

Telly prepares Elmo to welcome the viewer, but Elmo doesn't know what the word "welcome" means. Telly finds he can't describe what it means to him, so he runs off to find someone who can help him. Elmo liked the song (and the cute froggies) when Telly returns. He claims he consulted Big Bird, Ernie, Cookie Monster, and Mr. Snuffleupagus, none of whom could tell him what "welcome" means. Sponsors: A, V, 4