Scrum is a framework surrounding your existing workflow.
The Scrum Guide (2020) is a free resource originally published around 2010 by Ken Schwaber & Jeff Sutherland to "help
people worldwide understand Scrum".
The scrum guide itself won't be repeated here, but scrum theory is explained among the other pages here on the site.

Here are the main ideas surrounding scrum.

A Scrum Team, inspired by the closely-knit rugby team concepts, regularly huddles up to review their plays- Is the team winning the game? Why or why not, and what can the team change in the next play to make them more winning?
A small team is able to make big plays when they take intentional moments to cause work output and product quality to increase, which focuses more value and reduces waste.

Scrum theory is supported by these three pillars:

A scrum team owns these team values:

There are only three dedicated roles on a scrum team at the same hierarchy level- as a team.

Each role has a subset of responsibilities. There are also these which the whole team is responsible:

These are the containers and pieces which have key roles with the team's project.

The scheduled cycle of events is the heartbeat of scrum. Within these events, the team becomes more efficient and wiser and they review and anticipate the work they are doing.

These are not explicitly mentioned in the scrum guide, but may have utilitarian function for the team.

Scrum and education/planning services are available for commission- see detail here.