话 (traditional 話) is beautifully literal: the speech radical 讠 beside 舌, the tongue. Words are what the tongue does. Few characters explain themselves this cleanly.
话 is talk itself: 说话 (to speak — with 说 you learned), 电话 (electric speech — telephone), 中国话 (Chinese speech). 听话 (listen-to-words) means to be obedient — what every parent asks of children. And 大话 (big words) is boasting. The tongue radical never lies: wherever 话 appears, someone is talking.
Speech 讠 + tongue 舌 — the tongue at work: WORDS.
打电话 is literally 'hit the electric speech' — 打 is Chinese's universal 'do' verb for actions.