What a work permit is

A work permit lets you work in Canada for a set period.

It is not an entry visa on its own: depending on your nationality you may also need a visitor visa or an electronic travel authorisation.

Two very different types

The difference between them changes everything about your file:

Employer-specific permit: ties you to one employer and requires a job offer
Open work permit: not tied to an employer, but available only in specific situations

What an LMIA is

An LMIA is an assessment of the effect hiring you would have on the Canadian labour market. The employer obtains it, not you. It is required in many cases, and other programs are exempt from it.

Anyone offering to sell you an LMIA or a job offer for a fee is putting your file and your future in Canada at serious risk. We do not work that way.

Source: canada.ca — Work permits