Some writers use like when they should have used such as instead.

When you suggest a category or give something as a type example, write like:

Uncle Bill often listens to crooners like Bing Crosby.

Here Bing Crosby represents a specific type of singers, crooners, who often perform in a sentimental way (think of Crosby’s version of White Christmas and you will understand!).

The sentence does not state that Uncle Bill actually listens to Bing Crosby, only that he listens to singers of that type.

When you specify singers that Uncle Bill listens to, use such as:

He collects vinyl records with singers such as Dean Martin, Fred Astaire, Perry Como, Tony Bennett and Nat King Cole.

These singers are generally known as crooners, and here we understand that Uncle Bill has their records.

Seafood such as octopus is healthy

Some more examples:

You should eat more fruits like oranges.

Citrus fruits such as tangerines, clementines and lemons are rich in C vitamin. 

Advanced tools like robots can reduce production costs.

Robots can take over more complicated tasks such as welding and grinding.

The course covers basic concepts of business administration such as accounting, finance, human resources and marketing.

A songwriter like Leonard Cohen will be remembered forever (Songwriters similar to Cohen will never be forgotten).

A songwriter such as Leonard Cohen will be remembered forever (Leonard Cohen will never be forgotten).

There should not be a comma or a colon after such as, but you can have a comma before such as. Leave out that comma if what comes after such as is additional and essential information.

To sum up:

Use like when you refer to a category (you imply comparison).

Use such as when you give actual examples (you imply inclusion).