I have designed a form, where users can upload a file from their computers. Problem is, the uploaded image string from database shows that it exists in (contentassets/....) folder.
Where can I find that? And how can I also give an order to the form to store the images anywhere else I want?
You can find all your uploaded files included the ones uploaded by the user using a form in the Project\App_Data\blobs. I am not completly sure you can see the form uploaded file from the assets panel at the right corner, but in form submissions you can see the image by clicking the link in the corresponding field
In addition, you can decide where to store the images by implementing a custom actor
maybe a webhook
If I understod you correctly you want to see the uploaded files in Episerver edit mode?
If that was the case then you need to go to your form and view the form submissions.
Other way to see the files in Edit mode is to
Where the files are physically? They are on your disk where ever you have configured the blobs to be stored. As already pointed out by Jorge (default place is where your appData basepath points to + /blobs/).
If you want to change where uploaded files (from Forms) are stored then have a look at post by Alf Nilsson.