What is 'Living'?
The most common definition of living is everything that has life i.e. which grows, reproduces and has senses (touch, smell, taste, etc). If we go into depth we can also add the features like metabolism, growth, irritability, adaptability, ability to self-replicate, self organize, and loads of other features to the meaning of life. The attributes of life are inherent in such minute structures as viruses, bacteria, and genes, just as they are in the whale and the giant Sequoia.
There is a basic living unit in every organism, the cell that increases its growth. This process differs in each organism, while the plants on one hand continue to grow by this cell division throughout their life, the animals on the other hand grow until a certain age; however the cell division does not completely stop. Afterwards it continues in certain tissues to replace the lost cells in the wear and tear. Similarly the growth process in unicellular organisms also takes place by cell division. One can observe their growth under microscope simply by counting the cells. One thing we must understand is that merely the increase in the mass is not growth although it's the important element of growth but it alone cannot be considered as growth. In this similar way the non living things too grow but that does not make them living. Lets look at the characteristics of life in different living organisms which distinguishes it from the non living and dead.