The difference between concrete and cement is simpler than you think

The main difference between concrete and cement is that concrete is a composite of cement, water and aggregates.

Cement is powdered hydrated limestone and other minerals; it has the property to absorb water and to act as a binder. Cement is a binding substance which has the property of binding together with other materials.

Concrete cannot be made without cement. Cement when mixed with aggregates and water, fills the space between aggregates particles and glues them. Cement the main ingredient in concrete, requires moisture to gain strength. If it is kept moist for seven days it will shrink less and produce fewer cracks and gain more strength.

Reinforced concrete includes a mat of rebar, metal, and/or mesh added to provide extra support against stresses which is laid out prior to concrete pouring.

Cement used in construction can be categorized as hydraulic and non-hydraulic. Hydraulic cement hardens when it comes in contact with water or moisture. Hydraulic cement when fully formed is a water resistant product. One common example of hydraulic cement is Portland cement which is also known as OPC (Ordinary Portland Cement). Non hydraulic cement is cheaper than hydraulic cement but its inability to use in wet environment and long drying time makes it a poor choice for most of the applications. This is where the hydraulic cement excels.

In a concrete, aggregates make up around 60% to 80% of the mixture. The balance is cement and water. Aggregates can be gravel, crushed stone, sand or recycled cement. The type and selection of the aggregates fully depends on the concrete application. Concrete properties depend in the ration of aggregates-water-cement. Water to cement ratio is very critical as less water will make it difficult to correctly mix concrete and more water will make the final product weak. Different types and sizes of aggregates can be used in a mix to form concrete. It is better if the aggregates are clean and without excess dust as dust can absorb a lot of water. Concrete mixer is used to mix aggregates, water and cement to make concrete. Concrete batching plant come in various capacities and offer separate weighing option for aggregates, cement and water.

Concrete initially is in a form of a semi-liquid and then it achieves solid state and hardness. Some of the advantages of concrete are that it is weather proof, durable, low maintenance, fire resistant, environment friendly and has high strength. The applications of concrete for construction are infinite.
Cement and concrete are distinctly separate products.