& is the and operator. For example

10011100 &
01001101 =
00001100

i.e. Both bits of the two operands have to be set so that the resulting bit is also set.

| is the or operator. For Example

10011100 |
01001101 =
11011101

i.e. If any or both bits of the two operands is set, then the resulting bit is set too.

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