Files with .plist extension contain properties and settings for Mac OS apps. They are saved in XML format – text or binary. The format is from Apple’s Core Foundation. Main plist files are Info.plist in .app packs.
Plist files store user settings and data for packages. They arrange content order. There are text or binary forms. Text can edit with editor. Binary not.
Developers create plist files defining configuration and metadata for macOS or iOS apps. They are XML, storing settings names and values. Developers often convert some plists to binary before delivery. Like user preference plists.
1305 file types have plist extension but usually not compatible. You must use different apps for each. Apple developed this format. It likely created with a Mac OS X program.
Can convert between binary and XML with plutil utility in MacOS. Suggested plist openers are listed below.
Xcode
Property List Editor