This rapporteur paper synthesizes the contributions presented at the 39th International Cosmic Ray Conference (ICRC 2025) concerning the structure of the Heliosphere, the mechanisms of Galactic Cosmic Ray (GCR) solar modulation, and the dynamics of Solar Energetic Particle (SEP) acceleration and transport associated with transient solar events. Several space-born experiments confirm charge-sign dependent drift effects across different solar polarities (𝐴) and highlight
particle-specific modulation differences. Sophisticated modeling approaches, including data-driven models and GPU-optimized codes, demonstrate improved capabilities in forecasting GCR transport and space radiation environments. We will give details on ground-based monitoring of short-term variations, such as Forbush Decreases (FDs) and Co-rotating Interaction Regions (CIRs), through Neutron Monitors (NMs) and Muon Detectors, establishing real-time space weather techniques. We will see new SEP results measured from space, and show promising Solar Neutron (SN) signatures that, eventually, will provide deep insights into particle acceleration sites. Finally, a list including some upcoming missions, that underscore the continuous effort to understand the highest-energy phenomena and mitigate space weather hazards, will be given.