This review focuses on the occurrence of large-amplitude, low-frequency fluctuations in the solar wind, a supersonic and super-Alfvénic plasma flow originating from the Sun. The solar wind exhibits strong turbulent characteristics, evolving towards a state similar to hydrodynamic turbulence described by Kolmogorov. The presence of a strong magnetic field in the solar wind makes low-frequency fluctuations typically described within magnetohydrodynamic (MHD) theory. However, due to its unique characteristics, solar wind turbulence contains features that are difficult to classify within a general theoretical framework. The review covers recent advances in understanding near-equatorial and polar turbulence in the 3D heliosphere, including observations from spacecraft such as Helios and Ulysses, as well as numerical simulations. Key topics include the dynamics and statistics of turbulence, the coupling between charged fluids and magnetic fields, scaling features, and the non-linear energy cascade. The review also discusses the application of dynamical systems theory to turbulence, the role of compressive turbulence, and the origin of high-frequency regions. The solar wind turbulence is studied as a laboratory for understanding collisionless plasma phenomena, particularly at low frequencies where high-amplitude fluctuations have been observed. The review highlights the importance of turbulence in various aspects of plasma behavior in space, such as solar wind generation, high-energy particle acceleration, plasma heating, and cosmic ray propagation. Keywords: Solar wind, Turbulence, Interplanetary space, Dynamical systems, Magnetohydrodynamics (MHD), Nonlinear phenomenaThis review focuses on the occurrence of large-amplitude, low-frequency fluctuations in the solar wind, a supersonic and super-Alfvénic plasma flow originating from the Sun. The solar wind exhibits strong turbulent characteristics, evolving towards a state similar to hydrodynamic turbulence described by Kolmogorov. The presence of a strong magnetic field in the solar wind makes low-frequency fluctuations typically described within magnetohydrodynamic (MHD) theory. However, due to its unique characteristics, solar wind turbulence contains features that are difficult to classify within a general theoretical framework. The review covers recent advances in understanding near-equatorial and polar turbulence in the 3D heliosphere, including observations from spacecraft such as Helios and Ulysses, as well as numerical simulations. Key topics include the dynamics and statistics of turbulence, the coupling between charged fluids and magnetic fields, scaling features, and the non-linear energy cascade. The review also discusses the application of dynamical systems theory to turbulence, the role of compressive turbulence, and the origin of high-frequency regions. The solar wind turbulence is studied as a laboratory for understanding collisionless plasma phenomena, particularly at low frequencies where high-amplitude fluctuations have been observed. The review highlights the importance of turbulence in various aspects of plasma behavior in space, such as solar wind generation, high-energy particle acceleration, plasma heating, and cosmic ray propagation. Keywords: Solar wind, Turbulence, Interplanetary space, Dynamical systems, Magnetohydrodynamics (MHD), Nonlinear phenomena