Supprising that none of these List vs IList questions (or answers) mentions the signature difference. (Which is why I searched for this question on SO!)
So here's the methods contained by List that are not found in IList, at least as of .NET 4.5 (circa 2015)
- AddRange
- AsReadOnly
- BinarySearch
- Capacity
- ConvertAll
- Exists
- Find
- FindAll
- FindIndex
- FindLast
- FindLastIndex
- ForEach
- GetRange
- InsertRange
- LastIndexOf
- RemoveAll
- RemoveRange
- Reverse
- Sort
- ToArray
- TrimExcess
- TrueForAll
