The bird in the image is most likely a Eurasian wren (Troglodytes troglodytes). It is a small, brown songbird that is common in Europe and Asia. It has a short, cocked tail and a thin, down-curved bill. The Eurasian wren is a good mimic, and its song is a loud, fast jumble of notes.
There are a few other possibilities, such as the Bewick's wren (Thryomanes bewickii) or the Carolina wren (Thryothorus ludovicianus), but the Eurasian wren is the most likely match. These three species are all very similar in appearance, but there are some subtle differences. For example, the Eurasian wren has a slightly shorter tail than the Bewick's wren and a slightly longer bill than the Carolina wren.
Here are some other features that can help you identify a Eurasian wren:
Size: About 4 inches long
Wingspan: About 6 inches
Weight: About 0.4 ounces
Plumage: Brown upperparts, buff underparts, barred wings, and a white belly
Habitat: Woodlands, gardens, and hedgerows
Diet: Insects and spiders