“Word” (upper case) generally refers to Christ, the living Word of God.
“word” (lower case) generally refers to the written word of God, sacred scripture.
And the Word became flesh and made his dwelling among us, and we saw his glory, (John 1:14)
Jesus is God’s logos (word), God’s reason, self-image, and discourse, consubstantial (of one substance) with the Father, who existed with the Father as the Second Person of the Trinity before creation.
The LORD begot me, the beginning of his works,
the forerunner of his deeds of long ago;
From of old I was formed,
at the first, before the earth.
When there were no deeps I was brought forth,
when there were no fountains or springs of water;
Before the mountains were settled into place,
before the hills, I was brought forth;
When the earth and the fields were not yet made,
nor the first clods of the world.
When he established the heavens, there was I,
when he marked out the vault over the face of the deep;
When he made firm the skies above,
when he fixed fast the springs of the deep;
When he set for the sea its limit,
so that the waters should not transgress his command;
When he fixed the foundations of earth,
then was I beside him as artisan;
I was his delight day by day,
playing before him all the while,
Playing over the whole of his earth,
having my delight with human beings.
(Proverbs 8:22-31)
That same Second Person of the Trinity - God’s logos - became a man and walked among us.
What was from the beginning,
what we have heard,
what we have seen with our eyes,
what we looked upon
and touched with our hands
concerns the Word of life—
for the life was made visible;
we have seen it and testify to it
and proclaim to you the eternal life
that was with the Father and was made visible to us
(1 John 1:1-2)
The living logos of God, the living Word of God, is the second person of the Trinity made visible to us, Jesus Christ.
His teaching has been captured as part of the written word of God.
-Tim-