Siblings refer to Full (or real), Half or Paternal (or consanguine), and Maternal (or uterine). The concurrent existence of one or more such relations is not frequent in the real world.
The classifications of siblings include siblings sharing the same Mother (i.e., Maternal siblings), share the same Father (i.e., Paternal siblings), and share the same both parents (i.e., Full siblings).
Under Islamic law, Muslim Siblings can inherit if no Sons (or Sons of Sons how low soever), no father (or father of father how high soever) survive under certain conditions with applicable Madhab's differences of opinion.
Maternal siblings inherit 1/6 (i.e., one-sixth) if single and 1/3 (i.e., one-third) if multiple. Full and Paternal siblings inherit fixed or prescribed, and Residuary share similar to children. Siblings can be either Full, Paternal, or Maternal.
To understand these relations better, Refer to the Inheritance law academy and "Islamic inheritance sharers and Residuary" to learn about siblings' shares. However, the residue is not left to distribute for the property under Awal (or Aul) scenario. Radd, on the other hand, is distributed to the residuary.
In the absence of brothers, the sister's share can vary in certain conditions due to the decrease or increase of total shares under the Radd and Awal (or Aul) scenario.
Certain Hajb (i.e., blocking or exclusion) rules apply to siblings. Full, Paternal, and Maternal Siblings are blocked by Sons (and Sons of Sons how low soever) and the father. Maternal Siblings are also blocked by the Father of Father how high soever. Paternal Grandfather (i.e., Father of Father) how high soever blocks the Full and Paternal Siblings as per Hanafi, but not as per Shafii, Maliki, and Hanbali. However, Husband or Wife cannot block siblings and their descendants. Refer to "Islamic Inheritance Blocking Rules" to learn more. Also, you can refer to the Siblings Islamic inheritance chart for more information.
You can learn more through the Islamic Inheritance course. We encourage you to read the Islamic inheritance law book, which includes exclusive details about Islamic inheritance sharers, shares, residuary, and distant kindred relatives.