If you're ever wondered what codes like "HB" or "2B" mean for your pencil, wonder no more. These "grades" refer to the hardness or softness of your pencil. Harder leads leave a fainter line while soft pencils leave a darker line.
"H" stands for "hardness". The higher the number here (2H, 4H, etc.), the harder the writing core and the lighter the mark left on the paper.
"B" stands for "blackness". Higher numbers here mean darker marks.
2B pencils are smooth to write and draw with. They smudge easily but their marks are readily erased. A standard sketching pencil.
2H pencils are extremely smudge-resistant, giving cleaner lines. Useful for outlines and technical drawings.
HB is the standard lead grade used for writing because it dark enough to be read clearly while having minimal smudging. In the middle as the grade suggests.