Magnetic Field of Solar Eruptive and Non-Eruptive Events

Large solar flares are often, but not always accompanied by coronal mass ejections (CMEs). This "eruptiveness" is controlled by local and global magnetic field conditions. The detailed mechanism has major implications on space weather prediction and exoplanet habitability, which however remains poorly understood. I will review recent advance on both observational and theoretical fronts. The role of high-resolution observations will be discussed.