If you want to take your store to the next stage and create a multi-language store, the first thing you have to cover is localization. Providing customers with content in their local language creates a personalized experience and encourages them to come back.
If you need to translate some text in Magento 2 you can use the Magento Inline Translate functionality.
How to Enable Translate Inline in Magento 2?
In order to enable it, your Magento needs to be in the default or developer mode. Then you need to go to Admin Panel > Stores > Settings > Configuration > Advanced > Developer > Translate Inline.
Choose whether you want it to be enabled for Storefront or for the Admin panel.
Note: if you don't know how to switch Magento modes, or just want to add translations in Magento 2 easier, use Magento 2 Translation Extension.
How to Use Magento 2 Translate Inline Tool?
We recommend you make sure that the Magento block cache, page cache, and translations cache are disabled before using the Translation Inline Tool.
In order to translate some text move cursor (mouse) to the very phrase, find a small book sign, and press it.
Then make a translation in the Custom field. Put the checkmark in the Store View Specific section for indicating it for that language and for that store view specifically. If you want the new translation to be used for all the store views, please ignore this checkmark.
Press the Submit button and reload the page.
Once you finish, don't forget to disable the Translate Inline Tool, and re-enable Magento caches. For more convenient translation management configure Translation extension.