Lenders are the licensed professionals who give you the money either directly or through a third-party to fund your loan. Lenders have various names based on how they acquire their clients and what they do with your loan after it is funded.
Mortgage brokers are like a matchmaking service: They match you, the borrower, with a lender. They review your personal financial information and look over an array of lenders and try to match you with one who will give you the best rate and terms. The advantage is choice because the broker will have lots of lenders to match you with; the disadvantage is that once the match is made, the broker is out of the picture, so you may have difficulty staying in close touch with the person who is underwriting and funding your loan.
Loan officers find new clients, counsel borrowers on how to choose the best mortgage and fill out loan applications. They typically make their money through commissions on the loans. Loan officers can also be mortgage brokers if they also process and broker loans. Loan officers are sometimes called mortgage consultants, mortgage loan originators, home loan consultants, and mortgage planners.