A beamer talk usually needs two extra deliverables — a printable handout with the click-by-click overlays collapsed (often several slides per page), and speaker notes (for you, or a presenter display). beamer handles both, through handout mode and \note.
Handout mode — flatten for distribution
With \documentclass[handout]{beamer}, all overlays collapse and each frame becomes a single page (no \pause step expansion) — the right form for printing and sharing. Combine it with the pgfpages package to place several slides per sheet: \pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] (or 4 on 1), saving paper.
\documentclass[handout]{beamer}
\usepackage{pgfpages}
\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]Speaker notes — \note
\note{...} attaches notes to a frame (they do not appear on the slide itself). To display them, use \setbeameroption{show notes} (notes interleaved on their own pages) or, for a presenter display, \setbeameroption{show notes on second screen=right} (slides on one screen, your notes on the other).
\setbeameroption{show notes on second screen=right}
...
\begin{frame}{タイトル}
本文。
\note{ここで補足を一言。}
\end{frame}A handout with notes beside each slide
For a printed handout that also shows your notes beside each slide, the handoutWithNotes package adds layouts like \pgfpagesuselayout{3 on 1 with notes}[a4paper] — three slides down the page with a note column alongside. Handy for lecture notes.