The symbol is a symbol from a bygone era until the present is something different from the original, so easy to understand. Currently, the most widely used tool for many symbols, such as the math, flag, logo.
Symbols are dated from a bygone era Until now, some symbols different from the original. For simplicity, At present, the most commonly spread such as mathematical symbols, flag, logo.
The symbol has since the past. Until now, some symbols differ from the original, easy to understand The current symbol is very widely used often, such as mathematical symbol sign, flag, logo.