Here's a breakdown of how widgets work in Odoo, along with some examples to help you understand how to use them. This should clear up any confusion about customizing your field displays. The widget attribute customizes the UI rendering of a field in form, tree/list, kanban, or other views. It doesn't change the data type—only the way it's presented or interacted with. 

Field Type - Widget Name - Purpose / Effect
char,text - email - Renders as a mailto link
char - url - Renders as a clickable URL
char - phone - Renders as a clickable phone link (tel:)
boolean - toggle_button - Renders a switch-style toggle (often in tree/list view)
many2one - selection - Dropdown with text instead of a search field
many2one - radio - Renders as radio buttons
float - monetary - Adds currency symbol automatically
date - datetime - Date or datetime picker widget
html - html - Renders WYSIWYG HTML editor
binary - image - Renders as an image preview
binary - file - Renders as a file download/upload
selection - statusbar - Renders selection as a progress bar (used in stages/workflows) many2many - tags - Displays selected records as labeled tags

Examples:

Binary image -
Phone field with widget -

Status field with progress bar - 

Monetary field -