The STM32F-SOCKET64 board features a TQFP-64 socket that fits the STM32F series in TQFP-64. This board is designed to work with most devices in this series that come in a TQFP-64 package. The board is based on our extensive line of STM32F target devices, you can see information about them at https://rtfm.newae.com/Targets/UFO%20Targets/CW308T-STM32F/ .
A switch is used to swap between two of the most common pinout variants - one with an internal regulator (such as STM32F415), and one without an internal regulator (such as STM32F303). See the previous link for details of the two major pinout variants.