Quality objectives are overall goals or targets stated by the organization in order to achieve improvement within the QMS. A key performance indicator (KPI) is a metric used to evaluate factors that are crucial for the objective to be fulfilled. So, each objective can have one or more KPI. For example, objective can be to have highly educated employees. KPI's for this objective can be a percentage of employees actually trained in a given period, the number of certificates awarded to them, or the number of publications and conference contributions published by employees of the company.
Quality objectives have a strategic role in carrying out the quality policy and its implementation through a quality management system and provide a means to assess whether the QMS achieves its goals. There is no prescribed how many objectives you need to have, it is totally up to the management decision. Standard goals can be: meeting customer and regulatory requirements, achieving the improvement of the QMS and its products, and enhancing customer satisfaction.
In this article, you have more information about setting good quality objectives:
Setting good quality objectives for ISO 13485 https://advisera.com/13485academy/knowledgebase/setting-good-quality-objectives-for-iso-13485/
Although these articles are related to ISO 9001, they can help you to understand the differences between objectives and KPIs:
How to define Key performance indicators for a QMS based ISO 9001: https://advisera.com/9001academy/24/define-key-performance-indicators-qms-based-iso-9001/-iso-9001/
How to write good quality objectives: https://advisera.com/9001academy/knowledgebase/how-to-write-good-quality-objectives/