A redirect is when a customer goes to a page and then gets redirected to a new page. An example of this might be a customer who might want to visit yourwebsite.com and as they are viewing the website on a mobile phone, they get redirected to a mobile version of the website at mobile.yourwebsite.com
Avoiding redirects will mean that your website will load faster for the customer. If a customer is redirected then their browser makes additional calls to your server to get the page to render on the device they are using and this slows down viewing of your page and creates a poor experience for the customer.
Using responsive web design for your web pages will ensure your pages are loaded fast. Otherwise, your web developer needs to minimise or eliminate redirects where possible. It is best to ask your web developer to use responsive web design.