Click to select a single key. Selecting a key deselects all other selected keys. The Curves view displays the selected key with its tangents.
Click to select a single key. A selected key shows its tangents.
To select contiguous keys along the same animation curve, click the first key, then hold Shift and click the last key.
Hold Shift and click a key to select contiguous keys
There are many ways to select and deselect keys in the Curves view: