Maintenance assumes solving website programming issues, question-issue service, correcting errors, omissions, integrating certain changes or emerging technological innovations, adapting the site to new hosting standards, etc.
Maintenance assumes posting, updating, working with pictures and videos, creating new sections, re-design, monitoring of website content. In general, it includes any action related to the website content.
Service includes ensuring website security, regular archiving, protection from attacks, recovery in case of damage.