Libido

Also known as eros.

Psychic energy related to the life instinct.

Freud

Freud initially linked libido to sexual instinct but was later expanded.

Carl Jung

Jung and analytical psychologists adopt a non-sexual viewpoint on libido.

Fairbairn

In W.R.D. Fairbairn's writings libido is object seeking.

he labeled one of the subegos the “libidinal ego,” but, like many radical thinkers, he changed the meaning of “libidinal”; his definition did not imply Freud’s concept of diffuse sexuality but signaled an attachment to and need for love from the object.

Celani, David. Fairbairn’s Object Relations Theory in the Clinical Setting (p. 59). Columbia University Press.

It's contrasted against "aggression" which acts in two ways:

• Central ego's repression of the libidinal ego (and its exciting object) and antilibidinal ego (and its rejecting object)
• The antilibidinal ego's attack on the libidinal ego and its exciting object

Fairbairn’s view ‘libido’ must be regarded, not as a thing in it self, but as the object-seeking drive of the primary natural ego or psychic self. The basic drive to object relations is at the same time the drive to self development and selffulfilment as a person. The importance of object-relations lies in the fact that without them the ego

Guntrip, Harry. Schizoid Phenomena, Object Relations and the Self (Karnac Classics) (p. 91). Taylor and Francis. Kindle Edition.

See also

• Libido via dictionary.apa.org