STM32 is an Arm Cortex-M processor based microcontroller family manufactured by ST Microelectronics. It comes up with a wide range of options with different microcontroller models for different needs.
Figure 1: STM32 Family 
High performance series offers higher performance products compared to other STM32 series, using ST’s Non-Volatile Memory (NVM) technology.
Mainstream series appeals to a wide range of needs. With its well-balanced device architecture, it easily meets the basic needs in the consumer market where cost and time to market are important. It offers a wide range of application support, from real-time applications such as motor control to more complex applications such as digital signal processing.
Ultra-low-power series offers products with a good balance of performance, power, safety and cost effectiveness for low energy consumption embedded system and application designers.
Wireless series, offers products with wireless connection support.
With their price, resource abundance and end-user support, STM32 development boards are very successful and popular in the field. ST Microelectronics produces 3 different series of development boards:
- Discovery boards carry the necessary infrastructure to demonstrate specific device features, and extensive software samples allow full exploitation of device features and added value. It is slightly more expensive than the Nucleo series development boards, but has more sensors on it.
Figure 2: STM32 Discovery
- Nucleo boards give users the chance to experiment and prototype new ideas with STM32 microcontrollers. They are very popular for their price, features and resource abundance. In addition to resembling Arduino cards with pin sets, all modules produced for Arduino boards can be used easily with this series. Nucleo boards are divided into three classes:
- Nucleo-32 cards are the lowest tier cards in the Nucleo series. They have Arduino Nano pin set.
- Nucleo-64 cards are the most popular and largest Nucleo class. Nucleo-64 boards have Arduino Uno pin set.
- Nucleo-144 cards contain the highest performing members of the Nucleo series. They have Arduino Mega pin set.
- Evaluation series contains the most advanced and expensive development boards produced by ST. Eval cards contain many external circuits such as transceivers, displays, and memory interfaces.
Figure 6: STM32 Eval
- STMicroelectronics. STM32 32-bit Arm Cortex MCUs
- STMicroelectronics. STM32 High Performance MCUs
- STMicroelectronics. STM32 Mainstream MCUs
- STMicroelectronics. STM32 Ultra Low Power MCUs
- STMicroelectronics. STM32 Wireless MCUs
- STMicroelectronics. STM32 Discovery Kits
- STMicroelectronics. STM32 Nucleo Boards
- STMicroelectronics. STM32 Eval Boards