一，photo
photo：
/ ˈfəʊtəʊ /
n. 照片 v. 拍照
photograph：
/ ˈfəʊtəɡrɑːf /
n. 照片，相片 v. 拍照，照相
photo通常特指相机拍出来的照片，photos可以是pictures,但pictures不一定是photos。
你喜欢用手机拍照么？
Do you like use the mobile phones to take photos?
你擅长拍照么？
Are you good at taking photos?
二，picture
picture：
/ ˈpɪktʃə(r) /
n. 图片，绘画；照片；肖像；图像 v. 想象；绘画，拍摄；描绘
picture通常指广义的视觉表现（visual representation）/图像，比如照片、图片、绘画，photos可以是pictures,但pictures不一定是photos。
这是一张公园的照片。
This is a picture of a park.
三，照片相关的一些英语表达
拍照片：
take a photo, take photos;
take a photograph, take photographs;
take a picture, take pictures
给......拍照，为......拍照：
take a photo of ..., take photos of...;
take a photograph of..., take photographs of...;
take a picture of ..., take pictures of...
请看这张照片：
Look at this photo!
Look at this photogragh!
Look at this picture!
请勿拍照，禁止拍照：
No Photos! No Photoing! Don't take photos!
No Photographs！No Photographing！Don't take photographs!
No Pictures! Don't take pictures!
美颜：beautifying
P图：photo editing, picture editing
滤镜：filter
相机，照相机：camera
数码相机：digital camera
他们在公园里拍了许多照片。
They took many photos in the park.