Pfizer is a research-based global biopharmaceutical company that discovers, develops, manufactures, markets, and distributes biopharmaceutical products worldwide. Its primary revenue streams are the sales of biopharmaceutical products, including medicines and vaccines, and it also provides R&D services to some biotech companies. Pfizer holds a leading market position due to its extensive product portfolio and global reach, and it maintains a competitive advantage through its robust R&D capabilities and global infrastructure.