What is hard consonant, soft consonant

[goodstudent]

There is this thing called hard consonant, soft consonant. What does it mean? What letters are hard consonant and soft consonant?

How do I know if a last name that starts with a hard consonant?
How do I know if a name is ending in a vowel?

I did google, but cannot find good information explaining it on english language.

 

[5jj]

I did google, but cannot find good information explaining it [STRIKE]on[/STRIKE] in [STRIKE]e[/STRIKE] English, [STRIKE]language[/STRIKE].

I googled 'hard consonant' and found this.