Outbound marketing is pushing your product to potential customers.
Think radio or television. It’s a one way communication.
While inbound marketing is pulling potential customers to your product.
Think content on social media. It’s a two way communication.
Inbound is permission based marketing where you build a relationship with your potential customer.
While outbound is interruption based marketing. You get people’s attention by interrupting.
Usually outbound is used as a short term tactical an inbound as a long term strategy.
Outbound focuses on targeting the mass audience thus costing more money for it to be successful.
Priority of outbound is on making sales.
Inbound focuses on creating valuable content that serve the potential audience thus costing more time.
This help builds a relationship with them which eventually giving you the permission to market to them.
One is not better than the other. Each serve a different purpose depend on your goal, audience and budget.