Use:

refreshApex is used to:

Refresh cached data retrieved from Apex methods.
Ensure data displayed in components is current after updates.
Reduce the need for full page reloads by updating specific parts of the UI.
Improve the performance of your application by managing cache efficiently.

AccountController.cls

public class AccountController {
    @AuraEnabled(cacheable=true)
    public static List<Account> getAccounts() {
        return [SELECT Id, Name, Industry FROM Account LIMIT 10];
    }

    @AuraEnabled
    public static void createAccount(String name) {
        Account acc = new Account(Name = name);
        insert acc;
    }
}

accountComponent.html

<template>
    <lightning-card title="Accounts">
        <lightning-button label="Refresh Accounts" onclick={handleRefresh}></lightning-button>
        <lightning-input label="New Account Name" value={newAccountName} onchange={handleNameChange}></lightning-input>
        <lightning-button label="Create Account" onclick={handleCreate}></lightning-button>
        
        <template if:true={accounts.data}>
            <template for:each={accounts.data} for:item="account">
                <p key={account.Id}>{account.Name} - {account.Industry}</p>
            </template>
        </template>
        <template if:true={accounts.error}>
            <p>{accounts.error}</p>
        </template>
    </lightning-card>
</template>

accountComponent.js

import { LightningElement, track, wire } from 'lwc';
import { refreshApex } from '@salesforce/apex';
import getAccounts from '@salesforce/apex/AccountController.getAccounts';
import createAccount from '@salesforce/apex/AccountController.createAccount';

export default class AccountComponent extends LightningElement {
    @track newAccountName;
    accounts;

    @wire(getAccounts)
    wiredAccounts(result) {
        this.accounts = result;
    }

    handleNameChange(event) {
        this.newAccountName = event.target.value;
    }

    handleCreate() {
        createAccount({ name: this.newAccountName })
            .then(() => {
                return refreshApex(this.accounts);
            })
            .catch(error => {
                console.error('Error creating account:', error);
            });
    }

    handleRefresh() {
        refreshApex(this.accounts);
    }
}

The refreshApex function in LWC is a powerful tool for keeping your data up-to-date without requiring full page reloads. By leveraging refreshApex, you can ensure that your components reflect the most current information from the server, enhancing the responsiveness and user experience of your Salesforce applications. The example provided demonstrates how to use refreshApex to refresh cached data after creating a new account, highlighting its practical usage and benefits in real-world scenarios.
Happy Coding!