First of all, its worth always remembering that HubSpot operates on single, universal contact database. Contacts in the database can have as many custom properties as you like that can be used to segment them. And a filter (CRM feature) or a list (Marketing Hub feature) are just saved, segmented views of that central database.
To answer your question, you can create, name save filters in the contacts screen that only show you contacts who meet your criteria.
If you have the marketing hub, you can create, name and save a list - which has more powerful segmentation options - of contacts that meet your criteria. You can also create a static list to which you add contacts manually, as opposed to automatically.
Either one of these can potentially be used to drive an email marketing campaign, but the way to do so would differ depending on the tools in your stack.
First of all, its worth always remembering that HubSpot operates on single, universal contact database. Contacts in the database can have as many custom properties as you like that can be used to segment them. And a filter (CRM feature) or a list (Marketing Hub feature) are just saved, segmented views of that central database.
To answer your question, you can create, name save filters in the contacts screen that only show you contacts who meet your criteria.
If you have the marketing hub, you can create, name and save a list - which has more powerful segmentation options - of contacts that meet your criteria. You can also create a static list to which you add contacts manually, as opposed to automatically.
Either one of these can potentially be used to drive an email marketing campaign, but the way to do so would differ depending on the tools in your stack.
If you click the account menu (top right) and choose account and billing followed by products and services it should tell you which marketing hub you have.
If you don't have lists in the contacts menu, then you probably are on free.
What was not covered in your answer, is how to manually and through signup forms apply the segmenting - tagging, custom properties or lists.
Right now I have the free CRM and it has a section (in a Contact's info) for List Membership. Does this imply that the free CRM also has Marketing Hub?
The free CRM does not automatically include the features of the Marketing Hub - but there is a free verison of the Marketing Hub you can activate.
The easiest way to apply segmentation at the form is to use hidden properties with pre-selected values. How you do this varies with which platform you use to create forms.