Magento 2 - Override base view file

Create file with name app/design/frontend/[VendorName]/[theme]/Magento_Tax/templates/pricing/adjustment.phtml.

base folder it's default fallbacks for all arias and used to share resources across of areas

Copy the adjustment.phtml file from base template and put it inside app/design/frontend/[VendorName]/[theme]/Magento_Tax/pricing/adjustment.phtml

For more information, you can get help from here

correct and if you need to change admin view base file for example:

vendor/magento/module-ui/view/base/web/templates/grid/listing.html

NOTE: this file is responsible for any grid in admin

you will have to create new admin theme and put template file in Magento_Ui folder inside new admin theme so that admin will call template from your theme location for example:

app/design/adminhtml/Vendor/Theme/Magento_Ui/web/templates/grid/listing.html

NOTE: I am putting this answer because i had one similar issue in admin side and i have posted question in magento stackexchange and i got solved it after long efforts so someone can get help from this answer.please check my question for more:

How can I add new Class in Magento2 sales grid?