Well boys and girls, the word of the day is PARAKLETOS.
This word is only used 5x in the NT and each time it is used by John [Jn 14.16, 14.26, 15.26, 16.7, and 1 Jn 2.1]. In John's gospel, it always refers to the Holy Spirit. In 1 John, it refers to Jesus. Some translate it "Helper" [NASB and ESV], "Counselor" [NIV], "Advocate" [NLT and NEB], and/or "Comforter" [KJV]. If there was one word that could encapsulate all of these translations, that would be the best one to use. This is why you might hear the Holy Spirit referred to as the Paraclete.
Greek generally uses two words that mean "another" ["allos" and "heteros"]. "Allos" means another of the same kind; "heteros" means another of a different kind. This is where we get the word "heterosexual" from. For example, in Gal 1.6-7 Paul is perplexed that the Galatians are leaving the gospel for a "heteros" gospel. He says that because it is a "heteros" gospel, it is really no gospel at all.
So, knowing that Jesus is our PARAKLETOS in 1 Jn 2.1, Jn 14.16 says that the Holy Spirit is an "allos" PARAKLETOS. This means that it is not merely a job description of the Holy Spirit to comfort and help us, but it is part of the character of the whole Godhead to be with and beside His own.