ATTINY88 is 8-bit microcontroller with 8Kbytes In-system Programmable Flash. The controller is designed for high performance and low power consumption and comes in various packages like DIP, QPF and QPN for different applications.
ATTINY45 is high performance, low power controller from ATMEL. It is an 8 bit controller based on Advanced RISC architecture. It is one of members of ATTINYXX series, popular because of its small size and features.
ATMEGA328P is high performance, low power controller from Microchip. ATMEGA328P is an 8-bit microcontroller based on AVR RISC architecture. It is the most popular of all AVR controllers as it is used in ARDUINO boards.