Both are referring to a group of words. However, there are some distinct differences between phrase and clause.
Phrase is a group of words that is:
My best friend
With the blue shirt
For 20-days
Clause is a group of words that:
Examples
The falcon soared. (independent)
While my guitar gently weep (dependent)
As I was scared (dependent)
It's a sentence on its own.
I ate the pineapple.
The bear roared.
That's not our rabbit.
It can't be a sentence on its own. Usually, this clause starts with subordinating conjunctions.
Because it was delicious,
Although it was dark,
While the salmon flocked,
Dependent clause starts with a relative pronouns (who, while, which, whose, where)
It's delightful to see that guy that sells the new Willamete cold brew coffee ice-scream.
That woman, who always wore a red hat, has the strength of a lion.
That one person, who can breach the pillar to its top, be crowned as leader.
That candy, which has the red and green stripe, is great!