Recently, stochastic thermodynamics has emerged as a method for studying systems that operate at energies of the order of thermal fluctuations. The theory is valid even when systems are driven far from equilibrium and has been used to study nonequilibrium nanoscale systems. A major achievement in this field was the connection made between stochastic thermodynamics and information theory, which gave birth to "information thermodynamics". Information thermodynamics relates information to other thermodynamic quantities, such as free energy and entropy, and has proved particularly successful in resolving apparent thermodynamic paradoxes, such as Maxwell's demon. Figure . A Rosetta Stone for chemical (reactions and co-conformational dynamics) and information thermodynamics descriptions of a molecular motor; two distinct but complementary accounts of the processes involved in a minimalist, autonomous, chemically-fueled, molecular rotary motor. a, Chemical structure of the rotary motor and the chemical reactions involved in its operation. The motor comprises a benzylic amide macrocycle (magenta) and a track with two fumaramide binding sites (yellow, non-deuterated; green, deuterated for analytical purposes). The macrocycle randomly shuttles between the two fumaramide sites when its path is not blocked by Fmoc groups (purple). The fueling reaction consumes the fuel (Fmoc-Cl) and attaches an Fmoc group to the track, while the waste-forming reaction removes the Fmoc group (allowing passage of the macrocycle) and generates waste species (dibenzofulvene and CO 2 ). The fueling reaction is catalyzed by a pyridine-based nucleophilic catalyst (e.g., 4-dimethylaminopyridine or the bulky catalyst shown in Fig. ). Note that both reactions are considered reversible, even when the backward reactions (i.e. regeneration of fuel via barrier removal and waste products reacting to give barrier) are extremely rare events. 41 b, Information thermodynamics description of free energy transduction in the rotary motor. In the chemical transitions, free energy is supplied to the motor (IF(µF -µW)), part of which is dissipated (T Σchem ). IF is the rate at which the motor reacts with the fuel, (µF -µW) the chemical potential difference between fuel and waste species, T the temperature, Σchem the entropy production rate of the chemical transitions. The rest of the free energy is supplied to the mechanical transitions either as energy ( Ė) or information (RT İ) flow, where R is the gas constant. Mechanical transitions dissipate this free energy (T Σmech ), generating directional motion of the macrocycle. When Ė + RT İ = 0, mechanical transitions are at equilibrium and no net mechanical displacement of the macrocycle can arise.