Inbound and outbound marketing strategies are different things yet both aim to increase customer engagement.
Inbound marketing in a nut shell is focusing on earning customer interest rather than buying attention by creating valuable content that naturally attracts potential customers and taking advantage of SEO and content platforms to get that value in front of clients.
Outbound marketing strategies on the other hand rely on direct advertising and traditional promotional methods to reach customers. This can include things like social media ads, banner displays, search marketing promotional events and anything else where you are proactively reaching out to your customers.
Another way to think about inbound vs outbound is like this. inbound is like a magnet while outbound is like a megaphone. The messaging and product behind them can be similar, but the strategy or getting your brand in front of customers is fundamentally a different in their approach to customer acquisition.
As marketers, it is important when determining your marketing strategy, how you are going to maximise your ROI for each of these approaches. Given your website is going to be the most likely conversion point for these strategies, you're going to want to make sure it is optimised.