Small juvenile plants which have just germinated.
Technically, a seedling is a young plant sporophyte that has developed from a plant embryo (which is contained in a seed).
A seedling will have an embryonic root, embryonic shoot and seed leaves. The seed leaves are different than adult leaves, and are usually a lot smaller and often a different shape. Plants are often classified by the number of seed leaves. Angiosperms (flowering plants) have one or two seed leaves. Monocots have only one pointed leaf, and include the grasses. Dicots have two (usually rounded) seed leaves. Gymnosperms can have more variation, for example pine seedlings have 8 seed leaves.
Use this tag for questions about caring for seedlings and any problems encountered. Seedlings are typically very delicate. They are susceptible to damping-off which is fungal mould problem that kills seedlings before any adult leaves can form.