Global Skepticism vs. Local Skepticism.

Global skepticism is the view that we cannot know (have justified beliefs about) anything.
Local skepticism is the view that we cannot know (have justified beliefs about) anything in a certain domain.
Popular domains for local skepticism include:

Induction

Induction is an inference:
 
FROM:
Observed Cases
TO:
Unobserved Case
or Generalization

Examples

I’ve observed numerous zebras and all have had stripes. Therefore, all zebras have stripes.

I’ve observed numerous zebras and all have had stripes. Therefore, the next zebra I observe will have stripes.

The sun came up today.
The sun came up yesterday.
The sun came up the day before that.
…
Therefore, the sun will come up tomorrow.
 

Induction vs. Deduction

Notice that none of these inductive arguments are deductively valid.
It’s possible that the premises are true, but the conclusion false.
(That is, it’s possible that the sun won’t rise tomorrow, or that we’ll discover a zebra without stripes, or fire that is cold, or a bottle that doesn’t fall when dropped.)

But we think that an inductive argument with true premises makes it very, very likely that the conclusion is true.

Hume advances a powerful skeptical argument against induction. He thinks that we have no reason to believe that a good inductive argument with true premises even makes the conclusion likely to be true.