An expression meaning that being told about something and actually seeing it are very different; firsthand experience can differ greatly from reports.
写真で見るのと、現地で見るのとでは風景が全然違うよ。見ると聞くとは大違いだ。
The scenery in photos and the scenery on location are completely different. Seeing it yourself is nothing like hearing about it.
彼の説明を聞いてもよく分からなかったが、実際に作業を見て初めて理解した。見ると聞くとは大違いだね。
Even after his explanation I didn't really understand, but when I actually watched the work I finally got it. Seeing is nothing like hearing.
工場見学に来て、見ると聞くとは大違いだと感じた。安全対策が想像以上に徹底している。
After coming on the factory tour, I felt that seeing it was entirely different from hearing about it. Safety measures are more thorough than I imagined.