This study explored the essential meaning of simulation experiences in nursing education by analyzing the experiences of nursing students who participated in simulation-based training using standardized patient (SP) and high-fidelity simulator (HFS). A total of 21 participants were divided into three groups (A, B, and C, with seven students each), and focus group interviews were conducted. Data were analyzed using Colaizzi’s phenomenological method. The findings revealed three common themes in simulation experiences using SP and HFS: team-based collaborative learning, learning and performance deepening, and internal conflicts and learning barriers. Specifically, experiences with SP resulted in the theme of encounters with patients perceived as real, while experiences with HFS generated the theme of achievements and confusion encountered during technical training. Analysis of the attributes and contents of these themes indicated that students recognized their roles within collaborative teams, appreciated the value of leadership, became more proficient through repeated practice, experienced immersive interactions and responses to unexpected situations, and showed learning progress through feedback. Conversely, moments of anxiety, tension, environmental constraints, and difficulties with immersion were also identified. Therefore, future studies on simulation-based practice should adopt mixed-methods designs that integrate qualitative data with key variables derived from experiential and transformative learning—such as immersion, stress, self-efficacy, and shifts in perspectives—to systematically verify the developmental processes underlying learners’ simulation experiences.