Siemens earns revenue through several industrial-technology segments, with Digital Industries (factory automation, software) and Smart Infrastructure (buildings, grids, electrification) as its two largest and highest-margin businesses -- Smart Infrastructure alone targeted 6-9% comparable revenue growth and a 17-18% profit margin for fiscal 2025. While Siemens still manufactures physical hardware -- factory automation systems, grid equipment, and (through its Mobility unit) high-speed trains -- an increasing share of profitability comes from industrial software: 'digital twin' tools like Teamcenter and NX that let corporations design, simulate, and operate physical factories and products before building them. Siemens built this software business almost entirely through acquisition: UGS Corporation ($3.5 billion, 2007) created the original PLM (product lifecycle management) base, Mentor Graphics ($4.5 billion, 2017) added electronic design automation, and Altair Engineering (about $10 billion, 2025) added simulation and AI-driven design tools, together forming what Siemens calls its Xcelerator software stack. The company also holds a majority stake in publicly listed Siemens Healthineers (medical imaging and healthcare technology, including the $16.4 billion Varian Medical Systems acquisition in 2021) after spinning off Siemens Energy entirely in 2020 to sharpen its focus on industrial technology. FY2025 revenue reached EUR78.914 billion with EUR10.387 billion in net income. Siemens' shift toward recurring software revenue mirrors a broader industrial-technology trend of selling outcomes and data rather than one-time equipment, a transition the company has pursued more through acquisition (UGS, Mentor Graphics, Altair) than through internal software development alone.