Most computers comes with popular EN language set known as US-ASCII can display different characters. A default character set popularly known as ISO1 introduced that can display special characters. A positive number associated with each character set and encoded in a table. These special characters looks likes ♣♠☻◘○♫♥♦•◙♂►◄☼♀♪

In general we can use these special characters from Start Menu >> Programs >> Accessories >> System Tool >> Character Map. Here we can choose any font from the dropdown list and simply copy the character we want. Each of these characters associated with an ALT+NUM key combination. One sample list of standard characters as follows

ALT+1 – ☺
ALT+2 – ☻
ALT+3 – ♥
ALT+4 – ♦
ALT+5 – ♣
ALT+6 – ♠
ALT+7- •
ALT+8- ◘
ALT+9 – ○
ALT+10 – ◙
ALT+11- ♂
ALT+12 – ♀
ALT+13 – ♪
ALT+14 – ♫
ALT+15 – ☼
ALT+16 – ►
ALT+17 – ◄
ALT+18 – ↕
ALT+19 – ‼
ALT+20 -
ALT+21 – §
ALT+22 – ▬
ALT+23 – ↨
ALT+24 – ↑
ALT+25 – ↓
ALT+26 – →
ALT+27 – ←
ALT+28 – ∟
ALT+29 – ↔
ALT+30 – ▲

In most keyboards you need use NUM pad with ALT key to type these symbols. Also, in few keyboards, it works while the NUM pad is off.

Few frequently used symbols -

ALT+0163 – £
ALT+0169 – ©
ALT+0174 – ®
ALT+0176 – °
ALT+0247 – ÷