Ladybugs (called ladybirds in some countries) are a family of beetles that includes the Asian Lady Beetle (Harmonia axyridis), among others. The Asian lady beetle has large white "cheeks" and a black "W" (or "M", depending upon how you look) on its head. Other ladybugs have a black head and, if they have white marks, they are not as large as the cheeks of the Asian lady beetle.
Asian Lady Beetle versus Ladybug comparison chart
Asian Lady Beetle
Introduction (from Wikipedia)
The Asian Lady Beetle is a large coccinellid beetle originally native to eastern Asia, but which has been introduced to North America and Europe to control aphids and scale insects. It is now common, well known and spreading in those regions.
Coccinellidae is a family of beetles, known variously as ladybirds (UK, Ireland, Australia, Pakistan, South Africa), ladybugs (North America), or lady beetles (preferred by some scientists). Lesser-used names include ladyclock, lady cow, and lady fly
Has black M/W on head and what could be called large white "cheeks"
Black head with at times smaller white marks on. White "cheeks" (if they appear) are not as large as Asian lady beetle's