Define strong acid and weak acids with examples?

Strong Acids - HCl (Hydrochloric acid), $H_{2}S{O}_4$ (Sulphuric acid)

Weak acids - $H_2{CO}_3$ (Carbonic acid), $H_2{SO}_3$ (Sulphurous acid)

A strong acid is any acid that ionizes completely in solutions. This means it gives off the greatest number of hydrogen ions or protons when placed in a solution.

A weak acid is an acid that dissociates incompletely, releasing only some of its hydrogen atoms into the solution. Thus, it is less capable than a strong acid at donating protons. These acids have higher pKa than strong acids, which release all of their hydrogen atoms when dissolved in water.