Writing is not the same as calligraphy.
Writing is the primary stage, and calligraphy is the advanced stage. The goal of practicing calligraphy is to write words in a standard, neat, clear and fluent way. It is feasible to meet the needs of our work and study.
Writing is a skill, which can be completed quickly in a short time as long as there is a method. The standard of calligraphy is that words should express the feelings of the writer. To have personality, to have your own style, mainly to see. Calligraphy is an art, which can't be accomplished overnight, and it needs a lifetime's investment.
If you want to compare calligraphy with calligraphy, it is like broadcast gymnastics and rhythmic gymnastics. The former can be practiced by anyone, while the latter is only suitable for professionals.