The conventions of 2x2x2

The colors of the faces:

The colors shown in the diagrams are the same as the original 2x2x2.

The gray color indicates that the color present in this location is of no interest for the exercise. This is much easier to understand.

Examples:

If I tell you that only the second layer remains to be made, it is easier to understand with this diagram:
Rather than with this one:

The movements:

They are noted in English because it is the international convention.

This is a 90° movement looking at the layer in question.

The following examples show rotation clockwise and then counterclockwise.

Examples:

Outer layer
Right layer

'R' for Right
Left layer

'L' for Left
Top layer

'U' for Up
Bottom layer

'D' for Down
Front layer

'F' for Front
Back layer

'B' for Back