Railfanning is a hobby where enthusiasts observe and document trains and railroads. This can include watching trains pass by, photographing them, and collecting information about different types of locomotives and railcars. Railfans often visit specific locations known for train activity, such as rail yards or scenic tracks. Many railfans also enjoy learning about the history of railroads and the technology behind trains. They may participate in online communities or attend events like train shows to share their passion. Overall, railfanning combines a love for trains with an appreciation for the engineering and history of rail transport.