Why is the care plan important and why is it important to check clients care plan?

What have you come up with so far?
You have to share with us what you have come up with on your own.

The question you ask is very very basic and the answer easily found, so seeing such a question posted, tells us you have possibly done no research on your own.
Try to figure it out first, using the resources you have.
Then come back, with what you think, and then we can offer guidance.

We don't mind homework questions, but no one will just give you answers.

So... what do you think?

Absolutely true! All nurses have had to answer this question at one time or another, now you're in the hot seat! Good luck!

the word PLAN may give you the answer.

Here's something just to get you started: patients and their conditions don't remain the same.

Here is another thing to get you started: no 2 patients are exactly alike.

it is absolutely important because the Joint Commission will look at them during surveys. it is important to update it so that they will know you glanced at it and signed it.

THIS!!
Also, no matter how heroically you cared for a patient,
if the care plan is not updated, your boss will lose it on you. It's one of those things that sometimes to be the most important thing of all, almost, sometimes. Okay, maybe i am exaggerating just a tad.

for real, it mostly felt like busy work, rarely if ever used it. Oh, i've written them, updated them, signed them, etc etc.

but USED one? not so much. Most of that stuff, we are all already doing anyway, per doctor order, or per common sense, per report info on current status or needs of pt, or per protocol of the unit, or your own body of knowledge, or whatever.
almost always something else is causing me to provide the specific steps of care that i am.

I can't recall a time, when i was needing help/advice/knowledge on how best to help my patient,
and i got much from a care plan. I guess it is a nice back up, in case there is focus for that pt, that no one had already initiated or thought of. Occasionally, i might see something on a care plan, that makes me want to double check something. As a checklist, i guess it could be worse, especially when first admitting a patient, can be helpful.

okay, maybe they are vaguely useful at times.

sorry, hope you get better answers.
or, perhaps, some places have more useful careplans than where i have worked.