Hi there @anoushka_ferrari and welcome to the community!
There are many terms that are used interchangeably and if you ask different people, you'll end up with different responses. Experience map, user journeys, service maps, service blueprints....at the end of the day, it's not about the name of the artefact we're creating. It's about building a shared understanding of key insights and to enable actionable results. Often the process of creating these artefacts is just as important as the actual artefact.
But here's a quick overview of the terms as I understand it:
* User Journey - this is a visual representation of the end-to-end journey (series of steps) that an individual takes when interacting with a service across channels, touchpoints, time and space.
* Experience map - for me, the experience map is a really interesting artefact for communication. It encompasses the user journey and may include a range of other things such as the staff's experience in delivering that service, the systems and processes to enable the service, opportunities, strategic insights, design principles, recommendations etc.
* User Journey Mapping - this refers to the process of creating the user journey.
* Experience Mapping - this refers to the process of creating the experience map. It is a collaborative, iterative process for synthesising and visualising the user's experience. In addition to the awesome UX Mastery links that @hawk provided, Adaptive path also has a useful guide to experience mapping.
* Process Flow - this tends to represent the business/organisation process
* User Flow - this tends to get used interchangeably with 'task flow' but this refers to the path a user takes through your product interface. e.g. Google -> landing page -> article page -> article page -> contact form
* Task flow - this is a detailed representation of the steps that a user will take within an application/app/website. Google (enter search term) -> landing page (select article link from side navigation) etc. You can possibly use the Hierarchical Task Analysis technique for this.
Other useful things:
* Empathy map - @chrisoliver you were asking about this one. This is a great technique to help teams better understand the users by framing it in terms of what the users Say, Do, Think and Feel and the needs that they may have. Useful in the analysis phase. Here's a useful article from Cooper about empathy mapping.
* Mental models - this is a great technique from Indi Young to help understand the behaviours and root motivations of our users. I find it particularly useful when the user's experience is not a linear flow (e.g. think of people who might be starting a business - they may not necessarily do research in a particular order but jump around depending upon their motivations).
For all of the above, the preliminary work you need to do is undertake both quantitative and qualitative research.
Hope this helps!