In the current scenario, manufacturing industries are rapidly moving towards customised production instead of mass production, to meet the current market competition. Industry 4.0 prompts the digitalisation time. Industry 4.0 emphasises intelligent products, potential customers, and change of industrial machine suits. The whole thing is digital; manufacturing systems, business models, machines, working and demand environments, products, and operators. It is interconnected inside the advanced and innovative view with the comparing virtual portrayal. The new Industrial Revolution carries significant changes to companies that should adjust their machines, frameworks, and workers' abilities to continue their business in an extremely competitive market. Industry 4.0 inventiveness has engaged an impressive concentration of industries and researchers. This paper comprises of 164 reputed research papers and addresses evolution of Industry 4.0, key technologies, initiatives by various nations in this era, review of empirical analysis on Industry 4.0, and presented a future scope in the area of Industry 4.0 regarding survey of barriers to adopt Industry 4.0, maturity of Industry 4.0 concept, and impact of key technologies of Industry 4.0 in the today's scenario. This paper will help to the existing and future industries, and researchers in the context of Industry 4.0. © 2022 Inderscience Enterprises Ltd.